Curved surface display device, vehicle and backlight assembly

ABSTRACT

A curved surface display device, a vehicle and a backlight assembly are provided. The curved surface display device includes a display panel, a first middle frame, a backlight assembly and a back plate. The first middle frame is located on a non-display side of the display panel and configured to support the display panel; the backlight assembly is located at a side of the first middle frame away from the display panel and includes an optical film and a second middle frame, the second middle frame is located at a side of the optical film away from the display panel; the back plate is located at a side of the backlight assembly away from the display panel. The back plate includes a bottom plate and a side plate disposed on an edge of the bottom plate, and the second middle frame is connected to the bottom plate.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of international applicationPCT/CN2019/126915 filed on Dec. 20, 2019, this application is also acontinuation in part of international application PCT/CN2020/093954filed on Jun. 2, 2020, all of these applications hereby incorporatedherein by reference in their entirety.

TECHNICAL FIELD

At least one embodiment of the present disclosure relates to a curvedsurface display device, a vehicle and a backlight assembly.

BACKGROUND

A curved surface display device can form a display region with a curvedshape. When the curved surface display device is applied to a large-sizedisplay device, the difference between a visual angle of a middle of thedisplay region and a visual angle of an edge of the display region canbe reduced to achieve a better display effect.

SUMMARY

At least one embodiment of the present disclosure provides a curvedsurface display device, a vehicle and a backlight assembly. The curvedsurface display device includes a display panel, a first middle frame, abacklight assembly and a back plate. The first middle frame is locatedon a non-display side of the display panel, and configured to supportthe display panel; the backlight assembly is located at a side of thefirst middle frame away from the display panel, and includes an opticalfilm and a second middle frame, the second middle frame is located at aside of the optical film away from the display panel, and configured tosupport the optical film; at least part of the back plate is located ata side of the backlight assembly away from the display panel. The backplate includes a bottom plate and a side plate disposed on an edge ofthe bottom plate, and the second middle frame is connected to the bottomplate.

In some examples, the bottom plate includes a bottom wall and a firstsupporting portion located outside an edge of the bottom wall, the firstsupporting portion is located at a side of the bottom wall facing thedisplay panel, the first supporting portion has a first supportingsurface facing the display panel, and the second middle frame includes asecond supporting portion having a second supporting surface facing thedisplay panel to support the optical film, and the second supportingportion is disposed on the first supporting surface of the firstsupporting portion.

In some examples, the second supporting portion of the second middleframe is fixed to the first supporting portion by a first fixing memberin a direction perpendicular to the first supporting surface.

In some examples, the second supporting portion includes a fixing holepenetrating through the second supporting portion in the directionperpendicular to the first supporting surface, the first fixing memberis located in the fixing hole, and in a direction parallel to the firstsupporting surface, a size of the fixing hole is greater than that ofthe first fixing member so that there is a gap between the first fixingmember and an inner side wall of the fixing hole.

In some examples, a hardness of a material of the second middle frame isgreater than that of a material of the first middle frame.

In some examples, a side of the first middle frame away from the displaypanel presses against the optical film.

In some examples, the bottom wall includes two first edges opposite toeach other, and the first edges are arc edges; the first supportingportion includes first arc strip portions corresponding to the firstedges, and a bending direction of the first arc strip portions is thesame as that of the first edges.

In some examples, the fixing hole is a round hole, and in a directionparallel to a diameter of the round hole, a size of the fixing hole isgreater than a size of the first fixing member.

In some examples, the fixing hole is an elliptical hole, a major axisdirection of the elliptical hole is parallel to the first edge, and asize of the fixing hole is greater than that of the first fixing memberalong a direction parallel to the first edge.

In some examples, the optical film includes a first sub-optical filmincluding a plurality of first edge portions; the second supportingportion includes a plurality of rims, at least one rim is configured tosupport at least one first edge portion, the at least one rim includes afirst positioning groove and at least one second positioning groove, theat least one first edge portion includes a first positioning portion andat least one second positioning portion, the first positioning portionis in the first positioning groove, and each second positioning portionis in a corresponding second positioning groove, in a normal temperatureenvironment, on each rim and the corresponding first edge portion,opposite sides of each second positioning groove in an extendingdirection of the rim are not in contact with opposite sides of thecorresponding second positioning portion in the extending direction ofthe rim, a difference between a size of the first positioning groove anda size of the first positioning portion in the extending direction ofthe rim is a first space, a difference between a size of each secondpositioning groove and a size of the corresponding second positioningportion in the extending direction of the rim is a second space, and thefirst space is smaller than the second space.

In some examples, the plurality of first edge portions include a firstsub-edge portion extending along a first direction and a second sub-edgeportion extending along a second direction, the first positioningportion on the first sub-edge portion is approximately located at amidpoint of the first sub-edge portion in the first direction, and theat least one second positioning portion includes a plurality of secondpositioning portions, and the plurality of second positioning portionslocated on the first sub-edge portion are distributed on both sides ofthe first positioning portion in the first direction.

In some examples, in the normal temperature environment, a plurality ofsecond spaces corresponding to the plurality of second positioningportions on the first sub-edge portion gradually increase in a directionfrom the midpoint to both end points of the first sub-edge portion.

In some examples, the plurality of first edge portions include a firstsub-edge portion extending along a first direction and a second sub-edgeportion extending along a second direction, and the at least one secondpositioning portion includes a plurality of second positioning portionslocated on a same side of the first positioning portion on the firstsub-edge portion.

In some examples, in the normal temperature environment, a plurality ofsecond spaces corresponding to the plurality of second positioningportions gradually increase in a direction from a position close to thefirst positioning portion to a position away from the first positioningportion.

In some examples, a length of the first sub-edge portion is greater thana length of the second sub-edge portion.

In some examples, the first positioning portion on the first sub-edgeportion includes a first protruding portion, each second positioningportion on the first sub-edge portion includes a second protrudingportion, a middle part of the second protruding portion includes anopening, a boss is disposed in the second positioning groovecorresponding to the second positioning portion on the first sub-edgeportion, and the opening is sleeved on the boss.

In some examples, in the normal temperature environment, opposite sidesof each boss in the first direction are not in contact with oppositesides of a corresponding opening in the first direction, and adifference between a size of the opening and a size of the boss in thefirst direction is a third space greater than the first space.

In some examples, a plurality of third spaces corresponding to theplurality of second positioning portions gradually increase in thedirection from the midpoint to both end points of the first sub-edgeportion.

In some examples, the second space between each second positioningportion and the corresponding second positioning groove includes atleast one of an expansion space and a contraction space, and in thenormal temperature environment, in the direction from the midpoint toboth end points of the first sub-edge portion, a plurality of expansionspaces corresponding to the plurality of second positioning portionsgradually increase, and/or a plurality of contraction spacescorresponding to the plurality of second positioning grooves graduallyincrease.

In some examples, the first edge portion further includes a thirdpositioning portion and at least one fourth positioning portion on thesecond sub-edge portion, and the rim of the second supporting portionconfigured to support the second sub-edge portion includes a thirdpositioning groove and at least one fourth positioning groove, the thirdpositioning portion is in the third positioning groove, and each fourthpositioning portion is in a corresponding fourth positioning groove, theleast one fourth positioning portion is located on a same side of thethird positioning portion in the second direction, in the normaltemperature environment, opposite sides of each fourth positioninggroove in the second direction are not in contact with opposite sides ofthe corresponding fourth positioning portion in the second direction,and a difference between a size of the third positioning groove and asize of the third positioning portion in the second direction is smallerthan a difference between a size of each fourth positioning groove and asize of a corresponding fourth positioning portion in the seconddirection.

In some examples, the opening of the second positioning portion on thefirst sub-edge portion close to the third positioning portion contactswith or keeps a small distance from a side of a corresponding boss awayfrom the third positioning portion in the second direction, and a spacebetween a side of the third positioning portion away from the fourthpositioning portion and a corresponding side of the third positioninggroove is smaller than a space between a side the third positioningportion close to the fourth positioning portion and a corresponding sideof the third positioning groove to realize an accurate positioning ofthe first sub-optical film in the second direction; a space between theside of the third positioning portion away from the fourth positioningportion and the corresponding side of the third positioning groove issmaller than two spaces between two sides of each fourth positioningportion and a corresponding fourth positioning groove.

In some examples, the optical film further includes a second sub-opticalfilm including a plurality of second edge portions, the secondsub-optical film being located between the first sub-optical film andthe second supporting surface of the second middle frame, the secondsupporting surface being configured to support the second sub-opticalfilm and the first sub-optical film, and at least one of the pluralityof rims being configured to support at least one second edge portion; atleast one rim of the second supporting portion further includes aplurality of blocking walls, and at least one second edge portionincludes a plurality of concave portions, the plurality of concaveportions are disposed in one-to-one correspondence with the plurality ofblocking walls, and each concave portion is configured to be clampedwith the corresponding blocking wall to fix the second sub-optical film.

In some examples, the second sub-optical film includes a third sub-edgeportion extending along the first direction and a fourth sub-edgeportion extending along the second direction; the plurality of concaveportions include a first sub-concave portion and a plurality of secondsub-concave portions located on the third sub-edge portion, the firstsub-concave portion is approximately located at a midpoint of the thirdsub-edge portion in the first direction, and the plurality of secondsub-concave portions are distributed on both sides of the firstsub-concave portion; in the normal temperature environment, oppositesides of each second sub-concave portion in the first direction are notin contact with opposite sides of a corresponding blocking wall in thefirst direction, a difference between a size of the first sub-concaveportion and a size of a corresponding blocking wall in the firstdirection is a fourth space, a difference between a size of the secondsub-concave portion and a size of the corresponding blocking wall in thefirst direction is a fifth space, the fourth space is smaller than thefifth space.

In some examples, a length of the third sub-edge portion is greater thana length of the fourth sub-edge portion.

In some examples, in the normal temperature environment, in a directionfrom a middle point to both end points of the third sub-edge portion, aplurality of fifth spaces corresponding to the plurality of secondsub-concave portions gradually increase.

In some examples, the plurality of concave portions include a thirdsub-concave portion and at least one fourth sub-concave portion locatedon the fourth sub-edge portion, the at least one fourth sub-concaveportion is located on one side of the third sub-concave portion in thesecond direction, and in the normal temperature environment, adifference between a size of the third sub-concave portion and a size ofa corresponding blocking wall in the second direction is smaller than adifference between a size of each fourth sub-concave portion and a sizeof a corresponding blocking wall in the second direction.

In some examples, each of the plurality of blocking walls includes twosub-blocking walls arranged in an extending direction of the rim wherethe blocking wall is located, and the first positioning groove, thesecond positioning groove, the third positioning groove or the fourthpositioning groove is disposed between the two sub-blocking walls, andin the normal temperature environment, an edge of the first edge portionof the first sub-optical film except the first positioning portion, thesecond positioning portion, the third positioning portion and the fourthpositioning portion has an interval with the blocking walls.

In some examples, a convex structure is disposed between two adjacentconcave portions in the plurality of concave portions, and the convexstructure is located in an interval between the two adjacent blockingwalls.

In some examples, the side plate is located outside the secondsupporting portion and surrounds the second supporting portion, andincludes at least one first avoiding groove, and each first avoidinggroove is opposite to the second positioning groove, the thirdpositioning groove or the fourth positioning groove, so that the secondpositioning portion extends into the first avoiding groove after passingthrough a corresponding second positioning groove, the third positioningportion extends into the first avoiding groove after passing through acorresponding third positioning groove, or the fourth positioningportion extends into the first avoiding groove after passing through acorresponding fourth positioning groove.

In some examples, the side plate further includes at least one secondavoiding groove, the second avoiding groove is opposite to the intervalbetween the two adjacent blocking walls, and the convex structureextends into the second avoiding groove after passing through acorresponding interval.

In some examples, a part of the side plate extending in the seconddirection includes two first avoiding grooves and one second avoidinggroove, and the second avoiding groove is between the two first avoidinggrooves.

In some examples, the bottom plate further includes a connecting portionconnecting the edge of the bottom wall with the first supportingportion, and the first supporting portion extends outward from an edgeof the connecting portion.

In some examples, the backlight assembly further includes a light sourcecomponent including light-emitting diodes arranged in an array, and areflective sheet which is located on a light-emitting surface of thelight source component and exposes the light-emitting diodes, and thelight source component is disposed on a side of the bottom wall close tothe display panel.

In some examples, the second middle frame further includes an extensionportion connected with the second supporting portion and partiallylocated at an inner side of the connecting portion of the back plate,and the extension portion extends in a direction close to the bottomwall; an end of the extension portion away from the second supportingportion presses against a periphery of the reflective sheet.

In some examples, an edge of the extension portion connected with thesecond supporting portion is located at an outer side of the end of anedge of the extension portion pressed against the reflective sheet, andthe edge of the extension portion connected with the second supportingportion is located at a side of the end of the extension portion pressedagainst the reflective sheet close to the display panel, so that aninner surface of the extension portion is formed as an inclined surface,and a reflectivity of the inclined surface is not less than that of thereflective sheet.

In some examples, the bottom wall includes two second edges opposite toeach other, the second edges are straight edges, and the light-emittingdiodes are located on a plurality of strip-shaped lamp plates, and anextending direction of each strip-shaped lamp plate is parallel to thesecond edges.

In some examples, the backlight assembly further includes at least oneadapter plate located at a side of the bottom wall facing the displaypanel, and each adapter plate is connected with at least twostrip-shaped lamp plates to provide driving signals.

In some examples, the bottom wall further includes two first edgesopposite to each other, and the first edges are arc edges; theconnecting portion is provided with a strip-shaped outlet hole, a partof the connecting portion provided with the strip-shaped outlet hole isconnected with the first edge of the bottom wall close to the adapterplate, and a major axis of the strip-shaped outlet hole is parallel tothe first edge.

In some examples, the curved surface display device further includes alight source driving plate located at a side of the bottom wall awayfrom the display panel, and the adapter plate is connected with thelight source driving plate through a wire led out from the strip-shapedoutlet hole.

In some examples, a side of the bottom wall away from the display panelis provided with an arc-shaped reinforcing rib, an extending directionof the arc-shaped reinforcing rib is the same as that of the first edge,and a strength of the arc-shaped reinforcing rib is greater than that ofthe bottom wall to prevent deformation of the bottom wall.

In some examples, the side plate extends from an outer edge of the firstsupporting portion toward the display panel, and the first middle frameincludes an outer rim surrounding the display panel, and a part of theouter rim is located at an outer side of the side plate and fixedlyconnected with the side plate.

In some examples, the first middle frame includes a third supportingportion configured to support the display panel, and the thirdsupporting portion has a third supporting surface facing the displaypanel, and the third supporting surface and an inner side of the outerrim surrounding the display panel are both provided with buffer members.

In some examples, the curved surface display device further includes afront frame located at a side of the first middle frame away from thebacklight assembly, and configured to press against surfaces of thedisplay panel and the outer rim of the first middle frame away from thebottom plate to ensure the curvature of the display panel and the firstmiddle frame.

In some examples, the front frame includes a front frame side walllocated on a side of the outer rim away from the side plate, and thefront frame side wall includes an elongated hole, so that the frontframe side wall is fixedly connected to the side plate through a secondfixing member penetrating through the elongated hole, and a minor axisof the elongated hole is substantially perpendicular to the firstsupporting surface, and in the extending direction of the minor axis, asize of the second fixing member is the same as a size of the minoraxis.

In some examples, four edges of the display panel are connected one byone to form four corners, and at least one of positions of the sideplate surrounding the four corners of display panel and facing the thirdsupporting surface is provided with a groove.

In some examples, a material of the first middle frame is a lightshielding material.

In some examples, the curved surface display device is a vehicle-mountedcurved surface display device.

At least one embodiment of the present disclosure provides a vehicle,including the curved surface display device as mentioned above.

At least one embodiment of the present disclosure provides a backlightassembly, which includes: an optical film including a plurality of edgeportions; a supporting frame including a supporting portion, thesupporting portion having a supporting surface facing the optical filmto support the optical film, the supporting portion including aplurality of rims, at least one rim being configured to support at leastone edge portion. The at least one rim includes a first positioninggroove and at least one second positioning groove, the at least one edgeportion includes a first positioning portion and at least one secondpositioning portion, the first positioning portion is in the firstpositioning groove, and each second positioning portion is in acorresponding second positioning groove. In a normal temperatureenvironment, on each rim and the corresponding first edge portion,opposite sides of each second positioning groove in an extendingdirection of the rim are not in contact with opposite sides of thecorresponding second positioning portion in the extending direction ofthe rim, a difference between a size of the first positioning groove anda size of the first positioning portion in the extending direction ofthe rim is a first space, a difference between a size of each secondpositioning groove and a size of the corresponding second positioningportion in the extending direction of the rim is a second space, and thefirst space is smaller than the second space.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to clearly illustrate the technical solution of embodiments ofthe present disclosure, the drawings of the embodiments or relatedtechnical description will be briefly described in the following; it isobvious that the drawings in the description are only related to someembodiments of the present disclosure and not limited to the presentdisclosure.

FIG. 1A is an exploded schematic diagram of a curved surface displaydevice provided by an embodiment of the present disclosure;

FIG. 1B is a sectional view of the curved surface display device shownin FIG. 1A in an assembled state;

FIG. 2A is a schematic plan view of a back plate shown in FIG. 1A;

FIG. 2B is a schematic cross-sectional view taken along line AA shown inFIG. 2A;

FIG. 2C is an enlarged schematic diagram at a position B in FIG. 2A;

FIG. 3A is a first cross-sectional view of an assembly structural of aback plate and a backlight assembly shown in FIG. 1A;

FIG. 3B is a second cross-sectional view of the assembly structure of aback plate and a backlight assembly shown in FIG. 1A;

FIG. 3C is an enlarged plan view of a connection between a second middleframe and a first supporting portion in an example of an embodiment ofthe present disclosure;

FIG. 3D is a schematic cross-sectional view taken along a line CC′ shownin FIG. 3C;

FIG. 3E is an enlarged plan view of a connection between a second middleframe and a first supporting portion in another example of an embodimentof the present disclosure;

FIG. 3F is a side structural diagram of a second middle frame shown inFIG. 3A;

FIG. 4A is a schematic diagram of a partial planar structure after asecond middle frame and an optical film shown in FIG. 3A are assembled;

FIG. 4B is a schematic plan view of the optical film shown in FIG. 4A;

FIG. 4C is a schematic plan view of a second middle frame provided byanother embodiment of the present disclosure;

FIG. 4D is a schematic plan view of the first sub-optical film disposedon the second middle frame shown in FIG. 4C;

FIG. 4E is a schematic plan view of the first sub-optical film providedby another example of the embodiment of the present disclosure;

FIG. 4F is a schematic diagram of a planar structure in which the firstsub-optical film and the second middle frame are matched;

FIG. 4G is a partial enlarged view of E1 region of the backlightassembly shown in FIG. 4F;

FIG. 4H is a partial enlarged view of E2 region of the backlightassembly shown in FIG. 4F;

FIG. 4I is a partial enlarged view of E5 region of the backlightassembly shown in FIG. 4F;

FIG. 4J is a partial enlarged view of E6 region of the backlightassembly shown in FIG. 4F;

FIG. 4K is a partial enlarged view of E7 region of the backlightassembly shown in FIG. 4F;

FIG. 4L is a partial enlarged view of E8 region of the backlightassembly shown in FIG. 4F;

FIG. 4M is a schematic diagram of a partial cross-sectional structure ofa backlight assembly provided by an embodiment of the presentdisclosure;

FIG. 4N is a schematic diagram of a planar structure of a secondsub-optical film provided by an embodiment of the present disclosure;

FIG. 4O is a schematic diagram of a planar structure in which a secondsub-optical film is matched with a second middle frame provided by anembodiment of the present disclosure;

FIG. 4P is a partial enlarged view of E9 region in the backlightassembly shown in FIG. 4O;

FIG. 4Q is a partial enlarged view of E10 region in the backlightassembly shown in FIG. 4O;

FIG. 4R is a partial enlarged view of E11 region of the backlightassembly shown in FIG. 4O;

FIG. 4S is a partial enlarged view of E12 region of the backlightassembly shown in FIG. 4O;

FIG. 4T is a partial cross-sectional view of a backlight assemblyincluding a back plate provided by an embodiment of the presentdisclosure;

FIG. 4U and FIG. 4V are two side views of a back plate;

FIG. 4W is a schematic diagram of a positional relationship among afirst sub-optical film, a second middle frame and a back plate;

FIG. 4X is a schematic diagram of a positional relationship among asecond sub-optical film, a second middle frame and a back plate;

FIG. 5A is a schematic plan view of a strip-shaped lamp plate in a lightsource component shown in FIG. 1A and FIG. 1B;

FIG. 5B is a schematic plan view of an adapter plate connected with thestrip-shaped lamp plate shown in FIG. 5A;

FIG. 5C is a schematic diagram of assembling a back plate and a lightsource component in the curved surface display device shown in FIG. 1A;

FIG. 5D is a plan view of a side of a back plate away from a displaypanel in the curved surface display device shown in FIG. 1A;

FIG. 5E is a partial side view of a connecting portion of a back plateshown in FIG. 1A;

FIG. 6A is a schematic partial cross-sectional view of the assembly of afirst middle frame, a backlight assembly and a back plate in the curvedsurface display device shown in FIG. 1A;

FIG. 6B is a schematic plan view of a first middle frame shown in FIG.1A;

FIG. 6C is an enlarged schematic diagram at a position D in FIG. 6B;

FIG. 6D is a schematic side view of a first middle frame in FIG. 6C;

FIG. 7A is a schematic plan view of a front frame shown in FIG. 1A;

FIG. 7B is a structural schematic diagram of a front frame side wall ofthe front frame shown in FIG. 7A;

FIG. 7C is an enlarged schematic diagram at a position E in a frontframe side wall shown in FIG. 7A;

FIG. 7D is a partial structural diagram of a connection between a frontframe and a back plate shown in FIG. 1A;

FIG. 8 is a schematic diagram of a curvature tolerance relationship of acurved surface display device provided by an embodiment of the presentdisclosure.

DETAILED DESCRIPTION

In order to make objects, technical details and advantages of theembodiments of the present disclosure apparent, the technical solutionsof the embodiments of the present disclosure will be described in aclearly and fully understandable way in connection with the drawingsrelated to the embodiments of the disclosure. It is obvious that thedescribed embodiments are just a part but not all of the embodiments ofthe present disclosure. Based on the described embodiments herein, thoseskilled in the art can obtain other embodiment(s), without any inventivework, which should be within the scope of the present disclosure.

Unless otherwise defined, the technical terms or scientific terms usedherein have the same meanings as commonly understood by one of ordinaryskill in the art to which the present disclosure belongs. The terms“first,” “second,” etc., which are used in the description and theclaims of the present disclosure, are not intended to indicate anysequence, amount or importance, but distinguish various components. Theterms “comprises,” “comprising,” “includes,” “including,” etc., areintended to specify that the elements or the objects stated before theseterms encompass the elements or the objects and equivalents thereoflisted after these terms, but do not preclude the other elements orobjects. The phrases “connect”, “connected”, etc., are not intended todefine a physical connection or mechanical connection, but may includean electrical connection, directly or indirectly.

The features such as “parallel”, “vertical” and “same” used in theembodiments of the present disclosure all include the features of“parallel”, “vertical” and “same” in strict sense, as well as situationssuch as “approximately parallel”, “approximately vertical” and“approximately same” which contain certain errors. Considering theerrors related to the measurement in discussion and the measurement ofspecific quantities (that is, limitation of the measurement system),“approximately” can mean that a value is within the acceptable deviationrange for a specific value determined by those of ordinary skill in theart. For example, “approximately” can mean within one or more standarddeviations, or within 10% or 5% of the specific value.

In the research, inventor(s) of the application found that a curvedsurface display device includes one middle frame, which is used tosupport a display panel in the display device and has a light shadingfunction on a periphery of the display panel. An optical film isarranged on a side of the middle frame away from the display panel, andan edge of the optical film includes a plurality of openings to besleeved on a plurality of protrusions disposed on an upper edge of aside wall of a back plate to fix the edge of the optical film. Becausethe thermal expansion coefficient of the optical film is quite differentfrom that of a metal material of the back plate, when they are deformedby expansion with heat and contraction with cold, a lamination effectbetween the edge of the optical film and the upper edge of the side wallof the back plate will become worse, which will cause the optical filmto wrinkle, thus affecting the display effect of the display device. Inaddition, a part of the optical film except the edge can also besupported by a plurality of pillars disposed on a side of the opticalfilm away from the display panel. Because the pillar only supports theoptical film, but is not fixedly connected with the optical film, whenthe curved surface display device is used in vehicles (such asautomobiles), a problem of unqualified vibration reliability will occur.For example, when the curved surface display device as mentioned aboveis used in a vehicle, friction and collision will occur between thepillar and the optical film, which will not only cause noise andabnormal sound, but also scratch the optical film, resulting in badproblems such as white spots and bright lines on the display screen.

Another curved surface display device includes one middle frame forsupporting an optical film and a display panel, which requires greaterhardness, and a supporting portion for supporting the optical film inthe middle frame has greater thickness. When the display device istested at an environment with high temperature and high humidity, avalue of expansion and contraction of a material of the middle framewill increase. For example, when the middle frame expands, it willinterfere with other structures such as a front frame, resulting inlight leakage. When the middle frame contracts, a fixation gap betweenthe middle frame and the optical film decreases, and the optical filmfolds, which leads to a poor display picture. In addition, an upper edgeof the middle frame and an upper edge of the side wall of the back plateare roughly positioned through a hook structure and the like, and thefixing mode of the middle frame and the side wall of the back plateleads to greater assembly tolerance, thereby affecting the curvatureaccuracy of the display device. In addition, in a case of the middleframe of the above mentioned curved surface display device having arelatively large thickness, not only the difficulty of processing andmolding is increased, but also a problem is caused so that the middleframe is difficult to deform in the process of fixing the middle frameand the back plate, which makes it difficult to match the curvature ofthe back plate.

In addition, the curvature deviation of the back plate, the middle frameand the front frame in the curved surface display device will affect thecurvature accuracy of the whole curved surface display device.Therefore, the curvature accuracy of the current large-size curvedsurface display device is only 10%.

Embodiments of the present disclosure provide a curved surface displaydevice, which includes a display panel, a first middle frame, abacklight assembly, and a back plate. The first middle frame is locatedon a non-display side of the display panel and is configured to supportthe display panel; the backlight assembly is located at a side of thefirst middle frame away from the display panel and includes an opticalfilm and a second middle frame, the second middle frame is located at aside of the optical film away from the display panel and is configuredto support the optical film; at least part of the back plate is locatedat a side of the backlight assembly away from the display panel. Theback plate includes a bottom plate and a side plate disposed on an edgeof the bottom plate, and the second middle frame is connected to thebottom plate. In the present disclosure, two middle frames are disposedin the curved surface display device, and the second middle frame isfixed on the bottom plate of the back plate to minimize the assemblytolerance, thereby improving the curvature accuracy of the displaydevice.

The curved surface display device, the vehicle and the backlightassembly provided by embodiments of the present disclosure will bedescribed below with reference to the drawings.

FIG. 1A is an exploded schematic diagram of a curved surface displaydevice provided by an embodiment of the present disclosure, and FIG. 1Bis a sectional view of the curved surface display device shown in FIG.1A in an assembled state. As shown in FIG. 1A and FIG. 1B, the curvedsurface display device sequentially includes a front frame 600, adisplay panel 100, a first middle frame 200, a backlight assembly 300,and a back plate 400.

For example, as shown in FIG. 1A and FIG. 1B, the display panel includedin the curved surface display device may be a liquid crystal displaypanel. The liquid crystal display panel may include an array substrate(not shown), an opposite substrate (not shown), and a liquid crystallayer (not shown) located between the array substrate and the oppositesubstrate.

For example, a side of the array substrate facing the opposite substratecan include a plurality of gate lines extending along one direction anda plurality of data lines extending along the other direction, and theplurality of gate lines and the plurality of data lines are arrangedcrosswise to define a plurality of pixel units arranged in an array.Each pixel unit can include a pixel electrode and a thin filmtransistor. The gate line is connected with a gate electrode of the thinfilm transistor to turn on or turn off the thin film transistor. Thepixel electrode is connected with one of a source electrode and a drainelectrode of the thin film transistor, and the data line is connectedwith the other of the source electrode and the drain electrode of thethin film transistor. The data line inputs voltage signals required fordisplaying pictures to the pixel electrode through the thin filmtransistor to realize the display of the array substrate.

For example, the opposite substrate may be a color film substrate, and aside of the color film substrate facing the array substrate may beprovided with a color film layer corresponding to the pixel unit and ablack matrix covering structures such as the gate lines and the datalines located in a non-display area. For example, a side of the colorfilm substrate facing the array substrate may also be provided with acommon electrode opposite to the pixel electrode, and the commonelectrode is configured to apply a common voltage to generate anelectric field with the pixel electrode to drive the liquid crystalmolecules in the liquid crystal layer to deflect. The liquid crystalmolecules are deflected to change the transmittance of the liquidcrystal layer, thereby realizing the display of the desired gray-scaleimage.

For example, the display panel 100 may further include a first polarizerdisposed on a side of the array substrate away from the oppositesubstrate and a second polarizer disposed on a side of the oppositesubstrate away from the array substrate. The first polarizer includes alight transmission axis extending along a first direction and polarizesbacklight incident in the first polarizer along the first direction. Thesecond polarizer includes a light transmission axis extending along asecond direction and polarizes light incident on the second polarizeralong the second direction. For example, the light transmission axis ofthe first polarizer and the light transmission axis of the secondpolarizer are perpendicular to each other.

For example, as shown in FIG. 1A and FIG. 1B, the backlight assembly 300is located on the non-display side of the display panel 100 to providebacklight for the display panel 100. For example, the backlight assembly300 provided by the embodiment of the present disclosure can be adirect-type backlight assembly, which includes a light source component330, an optical film 310 between the light source component 330 and thedisplay panel 100, and a reflective sheet 340 on a side of the lightsource component 330 facing the optical film 310.

For example, the light source component 330 includes light-emittingdiodes arranged in an array.

For example, in a direction from the light source component 330 to thedisplay panel 100, the optical film 310 may include a diffuser plate, afirst diffuser sheet, a prism layer and a second diffuser sheet stackedin sequence.

For example, the diffuser plate can be made of transparent materialssuch as polymethyl methacrylate (PMMA) or polycarbonate (PC), which isthick and has a light transmittance of 50%-80%. For example, for ahigher haze, the first diffuser sheet is generally made of polyethyleneterephthalate (PET) or polycarbonate, and is disposed on a side of thediffuser plate away from the light source component, so that the lightdistribution is more uniform. For example, the prism layer can be madeof serrated or wavy polymethyl methacrylate microstructures or the like,which has a good spotlight effect. For example, the second diffusersheet is made of a material with higher transmittance and lower haze,which can be used as a structure for protecting the prism layer.

A certain light mixing distance is set between the light sourcecomponent 330 and the diffuser plate, so that the light emitted by thelight source component 330 forms a uniform energy distribution betweenthe light source component 330 and the diffuser plate. For example, thefirst diffuser sheet, the prism layer, and the second diffuser sheet areconfigured to uniformly extract the light emitted from the light sourcecomponent 330.

For example, in order to improve the utilization rate of the lightsource, the backlight assembly 300 may further include the reflectivesheet 340 which is located on a light-emitting surface of the lightsource component 330 and exposes the light-emitting diodes, that is, thereflective sheet 340 includes opening areas corresponding to thelight-emitting diodes one by one to expose the light-emitting diodes.

For example, the back plate 400 is used to support the light sourcecomponent 330.

As shown in FIG. 1A and FIG. 1B, a first middle frame 200 is located onthe non-display side of the display panel 100, that is, between thedisplay panel 100 and the backlight assembly 300, and is configured tosupport the display panel 100. The backlight assembly 300 furtherincludes a second middle frame 320 located at a side of the optical film310 away from the display panel 100, and the second middle frame 320 isconfigured to support the optical film 310. The curved surface displaydevice provided by the embodiment of the present disclosure furtherincludes a back plate 400 located at the side of the backlight assembly300 away from the display panel 100, which includes a bottom plate 410and a side plate 420 disposed at an edge of the bottom plate 410, andthe second middle frame 320 is connected to the bottom plate 410 of theback plate 400. The above-mentioned “the second middle frame 320 isconnected to the bottom plate 410 of the back plate 400” means that thesecond middle frame is in contact with the bottom plate and is fixedlyconnected with the bottom plate in at least one direction. In thepresent disclosure, two middle frames are arranged in the curved surfacedisplay device, and only the second middle frame is fixed on the bottomplate of the back plate, so that the assembly tolerance can beminimized, and then the curvature precision of the display device isimproved.

For example, FIG. 2A is a schematic plan view of a back plate shown inFIG. 1A, and FIG. 2B is a schematic cross-sectional view taken along aline AA shown in FIG. 2A. As shown in FIG. 1A to FIG. 2B, the bottomplate 410 and side plates 420 of the back plate 400 form anaccommodation space to accommodate the backlight assembly 300. Thebottom plate 410 of the back plate 400 includes a bottom wall 411 and afirst supporting portion 413 located outside an edge of the bottom wall411. The bottom plate 410 further includes a connecting portion 412connecting the edge of the bottom wall 411 with the first supportingportion 413, the first supporting portion 413 extends outward from theedge of the connecting portion 412.

For example, the light source component 330 and the reflective sheet 340included in the backlight assembly 300 are both located on the surfaceof the bottom wall 411 at a side facing the display panel 100, and thebottom wall 411 is used for supporting the light source component 330and the reflective sheet 340.

The bottom wall 411 in the embodiment of the present disclosure is acurved surface structure for maintaining a predetermined curvature ofthe display panel 100. When the curved surface display device providedby the embodiment of the present disclosure is used for viewing, thebottom wall may be curved, that is, the edge of the bottom wall iscurved toward a side facing the display panel.

For example, as shown in FIG. 1A to FIG. 2B, the bottom wall 411includes two first edges 4111 opposite to each other, and the firstedges 4111 are curved edges, such as arc edges, so that the bottom wall411 is a curved surface structure. For example, the bottom wall 411 alsoincludes second edges 4112 opposite to each other. In the embodiment,the second edges 4112 are taken as straight edges, for example, but notlimited thereto. The second edge can also be a curved edge as long asthe bottom wall enclosed by the first edge and the second edge is acurved surface structure. FIG. 2B is a schematic cross-sectional view ofthe back plate taken along a plane parallel to the second edge accordingto an embodiment of the present disclosure, it can be seen from FIG. 2Bthat the bottom wall extends substantially along a straight line in adirection along the second edge. The first edge and the second edge asmentioned above refer to the edges defined by a part where the bottomwall connected with the connecting portion.

For example, when the display device provided by the embodiment of thepresent disclosure is a large-size display device, for example, when asize of the display device is greater than 40 inches, the length of thearc-shaped first edge 4111 is longer than that of the linear second edge4112 to achieve a better display effect.

For example, as shown in FIG. 1A to FIG. 2B, in a technical schemeprovided by an embodiment of the present disclosure, an arc-shapedreinforcing rib 500 is disposed on a side of the bottom wall 411 awayfrom the display panel 100, and an extending direction of the arc-shapedreinforcing rib 500 is the same as that of the first edge 4111, and thestrength of the arc-shaped reinforcing rib 500 is greater than that ofthe bottom wall 411 to effectively bind the bottom wall 411, prevent thebottom wall 411 from deforming, and further ensure the curvature of thebottom wall 411. That is, the arc-shaped reinforcing rib 500 is disposedon the side of the bottom wall 411 away from the display panel 100 toprevent the bottom wall 411 from being deformed. For example, a materialof the arc-shaped reinforcing rib 500 can be galvanized steel plate witha thickness of 2 mm, and a material of the bottom wall 411 can bealuminum with a thickness of 1.5 mm.

For example, as shown in FIG. 1A to FIG. 2B, the arc-shaped reinforcingrib 500 may be located at the edge of the bottom wall 411 extending inthe extending direction of the first edge 4111 to better ensure thecurvature of the bottom wall.

Certainly, upon the second edge of the bottom wall being also in an arcshape, the side of the bottom wall away from the display panel can alsobe provided with an arc-shaped reinforcing rib extending along anextending direction of the second edge to further ensure the curvatureof the bottom wall.

For example, the arc-shaped reinforcing rib 500 can be connected withthe bottom wall by fasteners, such as screws or bolts.

For example, arc-shaped reinforcing ribs 500 may be provided on bothedges of the bottom wall 411 extending in the extending direction of thefirst edge 4111 on the side away from the display panel 100 to betterensure the curvature of the bottom wall 411.

For example, as shown in FIG. 1A to FIG. 2B, each arc-shaped reinforcingrib 500 may include a central portion 501 and an edge portion 502 fixedto the bottom wall 411, and a certain distance may be set between thecentral portion 501 and the bottom wall 411, that is, a hollow structuremay be set in the central portion 501, so as to ensure strength andcurvature while reducing weight.

For example, the hardness of a material selected for the arc-shapedreinforcing rib 500 is greater than that of the back plate to strengthenthe back plate strength and prevent the back plate deformation fromaffecting the curvature accuracy of the display device.

In the embodiment, the arc-shaped reinforcing rib at each edge is takenas a continuous reinforcing rib for description, but not limitedthereto. The arc-shaped reinforcing rib at any edge may also include aplurality of separated sub-reinforcing ribs, as long as the reinforcingrib can ensure the curvature of the bottom wall, and the number andshape of the arc-shaped reinforcing ribs are not limited in theembodiment of the present disclosure.

For example, when the display device in the embodiment of the presentdisclosure is used in occasions such as vehicle-mounted display orcommercial display, a plurality of support columns (not shown in thefigure) may be provided on a side of the above-mentioned arc-shapedreinforcing rib away from the bottom wall to fix the display device. Forexample, in the extending direction of the arc-shaped reinforcing rib, aplurality of support columns are arranged at the central portion of thearc-shaped reinforcing rib to fix the curved surface display device onthe vehicle.

For example, as shown in FIG. 2A, for example, the connecting portion412 may be a structure that surrounds the bottom plate 410, and theconnecting portion 412 is used to form a light mixing cavity between thelight source component 330 and the optical film 310 so as to form acertain light mixing distance between the light source component 330 andthe optical film 310. The embodiments of the present disclosure are notlimited thereto, for example, it is possible that the connecting portionis only provided at positions where the two first edges of the bottomwall are located, that is, the connecting portion connected with thebottom wall is not provided at the second edge of the bottom wall, andthen the first supporting portions only include curved partscorresponding to the two first edges.

For example, as shown in FIG. 1A to FIG. 2B, the connecting portion 412is located at the edge of the bottom wall 411 and extends from thebottom wall 411 towards the display panel 100. For example, the end ofthe connecting portion 412 away from the bottom wall 411 is locatedoutside the connecting position between the connecting portion 412 andthe bottom wall 411, so as to facilitate the integrated molding of thebottom wall and the connecting portion. Embodiments of the presentdisclosure are not limited thereto, and the connecting portion may beperpendicular to the second edge of the bottom wall as long as thebottom wall and the first supporting portion can be connected.

For example, as shown in FIG. 1A to FIG. 2B, the bottom plate 410further includes a first supporting portion 413 extending outward fromthe edge of the connecting portion 412 away from the bottom wall 411,and the first supporting portion 413 is located on the side of thebottom wall 411 facing the display panel 100.

For example, the first supporting portion 413 may be a continuousannular structure surrounding the display panel to support a secondmiddle frame mentioned later. Of course, it is not limited thereto, andthe first supporting portion may also be a discontinuous annularstructure as long as it can support the second middle frame.

As shown in FIG. 1A to FIG. 2B, the annular first supporting portion 413includes a first arc strip portion 4131 corresponding to the first edge4111, and a bending direction of the first arc strip portion 4131 is thesame as that of the first edge 4111. The bottom wall in the embodimentof the disclosure adopts a curved surface structure, and the first edgeof the bottom wall is an arc-shaped edge, so that the first supportingportion connected with the first edge of the bottom wall through theconnecting portion is formed into the first arc shaped strip portionhaving an arc shape.

For example, the back plate in the embodiment of the present disclosurecan be formed by an integrated die casting or stamping forming process,and the bottom plate of the back plate can be of an integral structure,that is, the bottom wall, the connecting portion and the firstsupporting portion are of an integral structure, thereby forming thefirst arc strip portion of the first supporting portion while formingthe curved surface bottom wall. For example, the back plate can beformed by stamping process. When the back plate is formed by stampingprocess, the resilience is large, and an additional structure is neededto ensure the curvature. The back plate can also be made by die-castingmolding process (molten iron flows into a designed mold and is cooledand molded) to reduce the resilience rate and dehydration rate of themolded material.

For example, the back plate can be made of aluminum or galvanized steelplate. The material of the back plate can meet the requirements ofactual product power consumption for heat dissipation performance. Whenthe display device has special requirements for temperature (forexample, when the white light brightness of the display device is 1000nits, the back plate temperature requirement is not higher than 48° C.),aluminum can be selected as the material of the back plate. When thedisplay device has no special requirements, the galvanized steel platecan be selected as the material of the back plate to reduce the cost.For example, the thickness of the bottom wall may be 1.5 mm, which isnot limited by the embodiments of the present disclosure.

For example, as shown in FIG. 1A to FIG. 2B, the first supportingportion 413 has a first supporting surface 4130 facing the display panel100, and the first supporting surface 4130 is used for supporting thesecond middle frame 320. For example, the first supporting surface maybe a continuous annular surface.

In the specification of the disclosure, the first supporting surface ofthe first supporting portion refers to a plane on a side of the firstsupporting portion facing the second middle frame to support the secondmiddle frame. The first supporting surface is defined as such a plane inorder to better explain the positional relationship between othercomponents and the first supporting surface, but it does not mean thatthe surface of the first supporting portion must be a plane. Forexample, in the case where the surface of the first supporting portionhas protrusion structures, the first supporting surface as a plane maybe a plane located at the bottom of these protrusion structures or aplane passing through a point on the surface of the first supportingportion. In a direction perpendicular to the first supporting surface, adirection from an opposite side of the first supporting surface of thefirst supporting portion to the first supporting surface is called“upper” direction, and a direction from the first supporting surface toan opposite side of the first supporting surface of the first supportingportion is called “lower” direction. Therefore, various positionalrelationships modified by “upper” and “lower” or “top” and “bottom” haveclear meanings. Such as an upper surface, a lower surface, a top walland a bottom wall. In addition, in a direction parallel to the firstsupporting surface, a direction from a center of the bottom wall to anedge is called the “outer” direction, and a direction from the edge ofthe bottom wall to the center is called the “inner” direction.Therefore, the relative position relationship modified by “inner” and“outer” has a clear meaning. For example, “inner side” and “outer side”.In addition, it should be noted that the above terms representingorientation are only exemplary and represent the relative positionrelationship of various components, and the combination of parts invarious devices or equipment of the present disclosure or the wholedevice or equipment can rotate at a certain angle as a whole.

For example, as shown in FIG. 1A to FIG. 2B, the side plate 420 of theback plate 400 extends from the outer edge of the first supportingportion 413 toward the display panel 100. For example, the side plate420 may be an annular structure that surrounds the display panel 100.

For example, FIG. 2C is an enlarged view at a position B in FIG. 2A. Asshown in FIG. 1A to FIG. 2C, four sides of the display panel 100 areconnected with one another to form four corners. The side plate 420 isprovided with a groove 421 at the position surrounding at least one ofthe four corners of the display panel 100 and facing the display panel100.

For example, the bottom plate 410 and the side plates 420 in the backplate 400 may be of an integral structure, and for example, the backplate may be formed by a die-casting or stamping process. In theembodiment of the disclosure, a groove is provided at one or more of thefour corners of the side plate, which can prevent extruded material fromstacking at the corner position of the side plate and forming aprotrusion when the back plate adopts a stamping process to form acurved surface structure, thereby ensuring the curvature of the firstmiddle frame and the front frame of the back plate at the side of theside plate away from the bottom wall, and further ensuring the curvatureaccuracy of the display device.

For example, FIG. 3A is a first cross-sectional view of the structure ofthe back plate and backlight assembly, and FIG. 3B is a secondcross-sectional view of the structure of the back plate and backlightassembly. As shown in FIG. 3A and FIG. 3B, the backlight assembly 300includes a light source component 330, a reflective sheet 340, a secondmiddle frame 320, and an optical film 310.

For example, as shown in FIG. 1A to FIG. 3B, the second middle frame 320includes a second supporting portion 321 disposed on the firstsupporting surface 4130 of the first supporting portion 413. The secondsupporting portion 321 is configured to support the optical film 310,that is, the second supporting portion 321 has a second supportingsurface 3215 facing the display panel 100 for supporting the opticalfilm 310.

For example, as shown in FIG. 3A and FIG. 3B, the second supportingportion 321 includes a first part 3216 for supporting the optical filmand a second part 3217 in contact with the first supporting portion 413of the bottom plate. A side of the first part 3216 of the secondsupporting portion 321 facing the optical film is provided with thesecond supporting surface 3215, and the second part 3217 of the secondsupporting portion 321 extends in a direction substantiallyperpendicular to the second supporting surface 3215 and contacts withthe first supporting portion 413. The first supporting portion 413supports the second middle frame 320 by supporting the second part 3217of the second supporting portion 321.

For example, the first supporting surface 4130 of the first supportingportion 413 of the bottom plate 410 is fixedly connected with the secondsupporting portion 321 of the second middle frame 320, that is, thesecond supporting portion 321 of the second middle frame 320 is fixed onthe first supporting portion 413 of the bottom plate 410. For example,the first part 3216 of the second supporting portion 321 is fixed on thefirst supporting portion 413 of the bottom plate 410.

For example, FIG. 3C is an enlarged schematic plan view of theconnection between the second middle frame and the first supportingportion in the embodiment of the present disclosure, and FIG. 3D is aschematic cross-sectional view taken along the line CC′ shown in FIG.3C. As shown in FIG. 1A to FIG. 3D, the second supporting portion 321 ofthe second middle frame 320 (for example, the first part 3216 of thesecond supporting portion 321) is fixedly connected with the firstsupporting portion 413 through a first fixing member 101, and the firstfixing member 101 extends in a direction perpendicular to the firstsupporting surface 4130 so that the first supporting portion 431 isfixedly connected with the second middle frame 320 in a directionperpendicular to the first supporting surface 4130. The connection ofthe second middle frame 320 to the bottom plate 410 of the back plate400 in the embodiment of the present disclosure may include that thesecond middle frame is fixedly connected with the bottom plate along thedirection perpendicular to the first supporting surface. In theembodiment of the disclosure, the second middle frame and the back plateare fixed in the direction perpendicular to the first supportingsurface, so that the second middle frame and the back plate can beaccurately positioned in the direction perpendicular to the firstsupporting surface, and the assembly tolerance can be minimized. Inaddition, a manner that the second middle frame and the back plate arefixed along the direction perpendicular to the first supporting surfacecan not only prevent the curvature of the second middle frame from beinginfluenced by the first fixing member, but also make the second middleframe and the back plate have a better fixed connection effect, so thatthe second middle frame can match the curvature of the back plate, thusbetter ensuring the curvature of the second supporting portion.

For example, the first fixing member 101 may be a nylon rivet, a screwor the like, which is not limited in the embodiment of the presentdisclosure.

For example, as shown in FIG. 1A to FIG. 3D, the second supportingportion 321 includes a first fixing hole 3210 penetrating the secondsupporting portion 321 in a direction perpendicular to the firstsupporting surface 4130, and the first supporting portion 413 of thebottom plate 410 includes a second fixing hole 4132 opposite to thefirst fixing hole 3210. The first fixing member 101 is located in thefirst fixing hole 3210 and the second fixing hole 4132. The first fixingmember 101 fixedly connects the second middle frame 320 with the firstsupporting portion 413 of the bottom plate 410 through the first fixinghole 3210 of the second supporting portion 321 and the second fixinghole 4132 of the first supporting portion 413, and a fixing directionbetween the second middle frame 320 and the bottom plate 410 isperpendicular to the first supporting surface. The above-mentionedsecond fixing hole may be a through hole, and at this time, the firstfixing member may be a nylon rivet or a screw, for example, the nylonrivet material is not easy to rust, is not affected by the humidity ofan external environment of the display device, and does not generateabnormal noise when the display device is in a vibration environment.The second fixing hole as mentioned above may also be a blind hole, andin this case, the first fixing member may be a screw.

For example, as shown in FIG. 1A to FIG. 3D, the first fixing hole 3210includes a first sub fixing hole 3211 and a second sub fixing hole 3212,and the first sub fixing hole 3211 is located at a side of the secondsub fixing hole 3212 close to the display panel 100. In the directionparallel to the first supporting surface 4130, the smallest size of thefirst sub fixing hole 3211 is greater than the largest size of thesecond sub fixing hole 3212 to form a step at a connection position ofthe first sub fixing hole 3211 and the second sub fixing hole 3212, aside of the step has a fixing surface 3214 facing the display panel sideand parallel to the first supporting surface, and the first fixingmember 101 is disposed in the first fixing hole to fix the second middleframe and the bottom plate.

For example, the first fixing member 101 may include a first sub fixingmember 1011 and a second sub fixing member 1012 connected to each other,and a third sub fixing member 1013 located at a side of the second subfixing member 1012 away from the first sub fixing member 1011. Forexample, the first sub fixing member 1011 and the second sub fixingmember 1012 may be an integral structure, and the third sub fixingmember 1013 is movably connected with the second sub fixing member 1012.For example, the first sub fixing member 1011 is located in the firstsub fixing hole 3211, the second sub fixing member 1012 is located inthe second sub fixing hole 3212 and the second fixing hole 4132 of thefirst supporting portion 413, and the third sub fixing member 1013 islocated on a side of the first supporting portion 413 away from thesecond supporting portion 321 to connect the third sub fixing member1013 and the second sub fixing member 1012 to fix the second middleframe and the bottom plate.

For example, a size of the first sub fixing member 1011 in the directionperpendicular to the first supporting surface is not greater than adepth of the first sub fixing hole 3211, so as to ensure the flatness ofa part of the surface of the second supporting portion for supportingthe optical film.

For example, in the direction parallel to the first supporting surface4130, the smallest size of the first sub fixing member 1011 is greaterthan the largest size of the second sub fixing member 1012 and thelargest size of the second sub fixing hole 3212, and the maximum size ofthe first sub fixing member 1011 is less than the smallest size of thefirst sub fixing hole 3211, and when the second sub fixing member 1012is disposed in the second sub fixing hole 3212, the first sub fixingmember 1011 can be pressed on the fixing surface 3214 (i.e., the firstsub fixing member contacts the fixing surface) to fix the second middleframe 320 on the bottom plate 410 in the direction perpendicular to thefirst supporting surface 4130.

For example, the first fixing hole and the through hole can be roundholes, and the size of the first fixing hole is greater than that of thefirst fixing member in a direction parallel to a diameter of the roundhole. For example, the diameter of the second sub fixing hole 3212 maybe 3.78 mm, the diameter of the second sub fixing member 1012 may be 3.0mm, and the diameter of the second fixing hole 4132 may be 3.1 mm. Ofcourse, embodiments of the present disclosure are not limited thereto.

FIG. 3E is an enlarged plan view of the connection between the secondmiddle frame and the first supporting portion provided by anotherexample of the embodiment of the present disclosure. As shown in FIG.3E, the first fixing hole 3210 may be an elliptical hole, and a majoraxis direction of the elliptical hole is in the extending direction ofthe first edge of the bottom wall, as long as the major axis size of thefirst fixing hole 3210 is greater than that of the first fixing member101.

For example, the first fixing hole 3210 in the example may also includea first sub fixing hole (not shown in the figure) and a second subfixing hole (not shown in the figure), and the first sub fixing hole islocated on a side of the second sub fixing hole close to the displaypanel. In a direction parallel to the first supporting surface 4130, theminimum size of the first sub fixing hole is greater than the maximumsize of the second sub fixing hole to form a step at a connectionposition of the first sub fixing hole and the second sub fixing hole, aside of the step has a fixing surface facing the display panel andparallel to the first supporting surface, and the first fixing member isdisposed in the first fixing hole to fix the second middle frame and thebottom plate.

For example, the first fixing member 101 may also include a first subfixing member (not shown in the figure) and a second sub fixing member(not shown in the figure) connected with each other, and a third subfixing member (not shown in the figure) located on a side of the secondsub fixing member away from the first sub fixing member. For example,the first sub fixing member and the second sub fixing member may be anintegral structure. For example, the first sub fixing member is locatedin the first sub fixing hole, the second sub fixing member is located inthe second sub fixing hole and the second fixing hole of the firstsupporting portion, and the third sub fixing member is located at a sideof the first supporting portion away from the second supporting portionto connect the third sub fixing member with the second sub fixing memberto fix the second middle frame and the bottom plate.

For example, in the direction parallel to the first supporting surface4130, the smallest size of the first sub fixing member 1011 is greaterthan the largest size of the second sub fixing member 1012 and thelargest size of the second sub fixing hole 3212, and the maximum size ofthe first sub fixing member 1011 is less than the smallest size of thefirst sub fixing hole 3211, and when the second sub fixing member 1012is disposed in the second sub fixing hole 3212, the first sub fixingmember 1011 can be pressed on the fixing surface 3214 (i.e., the firstsub fixing member contacts the fixing surface) to fix the second middleframe 320 on the bottom plate 410 in the direction perpendicular to thefirst supporting surface 4130.

For example, the first sub fixing hole may be an elliptical hole, and inthe major axis direction of the elliptical hole, a size of the first subfixing member is smaller than that of the first sub fixing hole. In aminor axis direction of the elliptical hole, a size of the first subfixing member is approximately equal to a size of the first sub fixinghole. The second sub fixing hole can be a round hole or an ellipticalhole. Upon the second sub fixing hole being an elliptical hole, in themajor axis direction of the elliptical hole, a size of the second subfixing member is smaller than that of the second sub fixing hole; in theminor axis direction of the elliptical hole, a size of the second subfixing member is approximately equal to a size of the second sub fixinghole.

Because the smallest size of the first sub fixing hole 3211 is greaterthan the largest size of the first sub fixing member 1011 and a size ofthe second sub fixing hole 3212 is greater than that of the second subfixing member 1012 in the direction parallel to the first supportingsurface, that is, the size of the first fixing hole is greater than thesize of the first fixing member in the direction parallel to the firstsupporting surface, there is a gap between an inner side of the firstfixing hole 3210 and an outer side of the first fixing member 101 in thedirection parallel to the first supporting surface 4130, the firstfixing member 101 is not contact with the inner side of the first fixinghole 3210. Therefore, upon the second middle frame being deformed in theprocess of expansion with heat and contraction with cold, the gap asmentioned above provides a space for expansion and contraction of thesecond middle frame, so as to avoid local bulging and other defects ofthe second supporting portion. While the second sub fixing member 1012penetrates through the second sub fixing hole 3212 and the second fixinghole in the first supporting portion 413, the second middle frame andthe bottom plate can be fixedly connected in a direction perpendicularto the first supporting surface by the way of the snap connectionbetween the second sub fixing member 1012 and the third sub fixingmember in combination with the way of pressing the first sub fixingmember 1011 on the fixing surface.

For example, FIG. 3F is a schematic side structure diagram of the secondmiddle frame shown in FIG. 3A. As shown in FIG. 1A to FIG. 3F, a shapeof a part of the second supporting portion 321 fixedly connected withthe first arc strip portion 4131 is arc-shaped. The partially arc-shapedsupporting portion is fixedly connected with the first arc strip portion4131 through the first fixing member 101 extending in the directionperpendicular to the first supporting surface 4130, and in an extendingdirection of the arc-shaped supporting portion, a size of the firstfixing member 101 is smaller than that of the first sub fixing hole sothat the first fixing member 101 can move in the first fixing hole 3210in a direction parallel to the first supporting surface 4130 relative tothe second middle frame 320.

The embodiment of the present disclosure adopts the second middle frameto support the optical film, and fixedly connects the second middleframe with the bottom plate of the back plate instead of fixedlyconnecting the second middle frame with the side plate of the backplate. Therefore, upon an arc-shaped supporting portion of the secondsupporting portion is deformed by expansion with heat and contractionwith cold, a distance reserved between the first sub fixing hole and thefirst fixing portion can prevent deformation such as a protrusion on aside of the arc-shaped supporting portion around the first fixingportion facing the display panel, which seriously affects the curvatureof the second middle frame and affects the optical film. In addition, inthe embodiment of the disclosure, the first fixing hole in the secondmiddle frame is only a through hole penetrated by the first fixingmember, rather than a threaded hole used for being engaged with thefirst fixing member (taking the first fixing member as a screw as anexample), so even if the expansion and contraction displacementgenerated by the arc-shaped supporting portion around the first fixingmember is large, the obstruction of the first fixing member may causelarge deformation of the fixing hole, and there will be no failure ofthe fixing hole. Therefore, the bottom plate and the second middle frameare fixedly connected by adopting the first fixing member extendingalong the direction perpendicular to the first supporting surface, sothat the first fixing member can be prevented from influencing thecurvature of the second supporting portion, and the curvature of thesecond supporting portion can be better ensured.

In an embodiment of the present disclosure, the bottom wall may be usedto maintain a predetermined curvature of the arc-shaped part in thesecond supporting portion.

For example, upon the second edge of the bottom wall being a straightedge, a strip-shaped part in the annular first supporting portioncorresponding to the second edge is also non-arc-shaped, and the secondsupporting portion disposed on the strip-shaped part is alsonon-arc-shaped.

For example, before connecting the second middle frame with the backplate, the second middle frame does not have a large curvature. Upon thesecond middle frame being connected with the first supporting portionthrough the first fixing member, the second supporting portion of thesecond middle frame bends according to the shape corresponding to thecurvature of the first supporting portion.

For example, as shown in FIG. 1A to FIG. 3F, the second middle frame 320further includes an extension portion 322 connected with the secondsupporting portion 321, and the extension portion 322 extends toward thebottom wall 411, and the end of the extension portion 322 away from thesecond supporting portion 321 presses against the periphery of thereflective sheet 340. In the embodiment of the present disclosure, whilethe second supporting portion included in the second middle frame isfixedly connected with the first supporting portion, the extensionportion included in the second middle frame is pressed against thereflective sheet arranged on the bottom wall to further fix the secondmiddle frame, prevent the second supporting portion from overturning andensure the stability of the second middle frame.

It should be noted that the above-mentioned extension portion pressesagainst the reflective sheet, which means that the extension portion isin contact with the reflective sheet, so that the bottom wall cansupport the extension portion, while the extension portion can fix thereflective sheet and prevent the periphery of the reflective sheet fromwrapping. FIG. 1A to FIG. 3F schematically show that the end of theextension portion away from the second supporting portion is pressedagainst the reflective sheet, and the extension portion in the actualproduct is in contact with the surface of the reflective sheet.

For example, as shown in FIG. 1A to FIG. 3F, an edge of the extensionportion 322 connected with the second supporting portion 321 is locatedat the outer side of the edge of the extension portion 322 pressingagainst the reflective sheet 340, and the edge of the extension portion322 connected with the second supporting portion 321 is located at aside of the end of the extension portion 322 pressing against thereflective sheet 340 close to the display panel 100, so that an innersurface of the extension portion 322 is formed as an inclined surface,and the inclined surface acts as a reflective surface, for example,reflectivity of the inclined surface is not less than reflectivity ofthe reflective sheet, so as to improve the utilization rate of the lightemitted by the light source component 330 and improve luminousefficiency. In the embodiment of the present disclosure, the secondmiddle frame is configured to support the optical film, and at the sametime, and to press the reflective sheet to form a light mixing spacebetween the light source component and the optical film.

For example, the material of the reflective sheet 340 has flexiblecharacteristics, and the reflective sheet 340 can form to be a curvedreflective sheet with a certain curvature by being arranged on thecurved surface bottom wall 411.

For example, the second middle frame 320 is made of a material withcertain hardness and flexibility. For example, the material of thesecond middle frame 320 may be polycarbonate (PC) mixed with 10% glassfiber, so as to ensure that the second middle frame has a predeterminedhardness.

For example, FIG. 4A is a schematic diagram of a partial planarstructure after a second middle frame and an optical film shown in FIG.3A are assembled, and FIG. 4B is a schematic plan view of the opticalfilm shown in FIG. 4A. As shown in FIG. 1A to FIG. 4B, a side of thesecond supporting portion 321 of the second middle frame 320 facing thedisplay panel is provided with a plurality of protrusions 3213, and anedge of at least one of films in the optical film 310 except a diffuserplate (for example, a first diffuser sheet and a second diffuser sheet)includes a plurality of openings 3200. The plurality of openings 3200correspond to the plurality of protrusions 3213 one by one to set atleast one film of the optical film 310 except the diffuser plate on thesecond middle frame 320, that is, the plurality of openings 3200 aresleeved on the plurality of protrusions 3213 one by one to set at leastone film of the optical film 310 except the diffuser plate on the secondmiddle frame 320.

In the technical scheme provided by the embodiment of the presentdisclosure, the second middle frame is used to support and fix theoptical film (for example, the diffuser plate is adhered to the secondsupporting surface). Because the thermal expansion coefficient betweenthe optical film and the second middle frame is close, upon the twomaterials being deformed by expansion with heat and contraction withcold, the bonding effect between the edge of the optical film and thesecond middle frame will not be affected, thus ensuring the curvature ofthe optical film. In addition, in the embodiment of the disclosure, thesecond middle frame has a good supporting effect on the optical film,and the arrangement of the supporting pillars can be omitted, so thatwhen the curved surface display device is applied to vehicles, such asautomobiles, the vibration reliability can also be improved.

A vehicle-mounted liquid crystal display module includes an edge-litbacklight source, which includes a structural member and an optical filmfixed on the structural member. Two opposite edges of the structuralmember are provided with grooves having a positioning column therein. Anedge of the optical film is provided with a protrusion, which include around hole matched with the positioning column. A surface of the opticalfilm facing the structural member is provided with double-sided adhesivetape to bond the optical film with the structural member, thusstabilizing the optical film when the vehicle-mounted liquid crystaldisplay module is applied to vehicle-mounted vibration conditions. Inthe research, the inventors of the application found that a fixing modeof the optical film and the structural member in the above-mentionedvehicle-mounted liquid crystal display module is similar to a fixingmode of an optical film in a general small-size liquid crystal displaymodule, with the difference that the optical film is also adhered withthe structural member through double-sided adhesive tape, thus reducingthe relative displacement between the optical film and structuralmember. This limiting mode with double-sided adhesive tape limits themoving space of the optical film. The environment in which thevehicle-mounted liquid crystal display module is located includes a hightemperature and high humidity environment besides a vibratingenvironment. For example, the vehicle-mounted liquid crystal displaymodule may be in a high temperature and high humidity environment with atemperature range of −40 to 95° C. and a relative humidity as high as90%. In a case where a reliability test of cold, hot and shock iscarried out on the optical film, the optical film will expand orcontract, and the double-sided adhesive tape arranged between theoptical film and the structural member limits the moving space when theoptical film expands or contracts, which will cause the optical film tohave wrinkles, warpage and other defects, thus affecting the displayscreen of the display device.

Another embodiment of the present disclosure provides a backlightassembly including a first sub-optical film and a supporting frame. Thefirst sub-optical film includes a plurality of first edge portions; thesupporting frame includes a supporting portion having a supportingsurface facing the first sub-optical film to support the firstsub-optical film, and the supporting portion includes a plurality ofrims, at least one of which is configured to support at least one firstedge portion. At least one rim of the supporting portion includes afirst positioning groove and at least one second positioning groove; atleast one first edge portion of the first sub-optical film includes afirst positioning portion and at least one second positioning portion,the first positioning portion is in the first positioning groove, andeach second positioning portion is in a corresponding second positioninggroove. In a normal temperature environment, on each rim andcorresponding first edge portion, opposite sides of each secondpositioning groove in an extending direction of the rim are not incontact with opposite sides of the corresponding second positioningportion in the extending direction of the rim, and a difference betweena size of the first positioning groove and a size of the firstpositioning portion in the extending direction of the rim is a firstspace, a difference between a size of each second positioning groove anda size of the corresponding second positioning portion in the extendingdirection of the rim is a second space, and the first space is smallerthan the second space. By setting distances between the two positioningportions of the first sub-optical film and the corresponding positioninggrooves differently, the combination of accurate positioning and roughpositioning can be realized, which can not only ensure the fixing of theoptical film and the supporting frame, but also ensure that the opticalfilm is not easy to wrinkle in a high temperature and high humidityenvironment, and does not affect the normal display. The backlightassembly provided by the embodiment of the present disclosure can beapplied to the curved surface display devices shown in FIG. 1 to FIG.4B, and can also be applied to other display devices, which is notlimited by the embodiment of the present disclosure.

For example, the supporting frame in the above embodiments may be thesecond middle frame 320 shown in FIG. 1 to FIG. 4B, and the supportingportion in the above embodiments may be the second supporting portionshown in FIG. 1 to FIG. 4B, but not limited thereto. The supportingframe in the above embodiments may also be different from the secondmiddle frame shown in FIG. 1 to FIG. 4B, and the supporting portion inthe above embodiments may also be different from the second supportingportion shown in FIG. 1 to FIG. 4B. For example, the first sub-opticalfilm in the above embodiment may be a part of the optical film 310 shownin FIG. 1 to FIG. 4B, but is not limited thereto, and may also bedifferent from the optical film shown in FIG. 1 to FIG. 4B.

Another embodiment of the present disclosure provides a backlightassembly, as shown in FIG. 4M, which includes an optical film 3101 and asupporting frame 320. The optical film includes a plurality of edgeportions; the supporting frame includes a supporting portion having asupporting surface facing the optical film to support the optical film,and the supporting portion includes a plurality of rims, at least one ofwhich is configured to support at least one edge portion. At least onerim includes a first positioning groove and at least one secondpositioning groove, at least one edge portion includes a firstpositioning portion and at least one second positioning portion, thefirst positioning portion is located in the first positioning groove andeach second positioning portion is located in the corresponding secondpositioning groove. In a normal temperature environment, on each rim andthe corresponding edge portion, opposite sides of each secondpositioning groove in an extending direction of the rim are not incontact with opposite sides of the corresponding second positioningportion in the extending direction of the rim, a difference between asize of the first positioning groove and a size of the first positioningportion in the extending direction of the rim is a first space, adifference between a size of each second positioning groove and a sizeof the corresponding second positioning portion in the extendingdirection of the rim is a second space, and the first space is smallerthan the second space. In this embodiment, the optical film may refer tothe first sub-optical film, the supporting frame may refer to the secondmiddle frame, and the edge portion may refer to the first edge portion.

For example, FIG. 4C is a schematic plan view of a second middle frameprovided by another embodiment of the present disclosure, FIG. 4D is aschematic plan view of a first sub-optical film disposed on the secondmiddle frame shown in FIG. 4C, and FIG. 4F is a schematic diagram of aplanar structure in which the first sub-optical film and the secondmiddle frame are matched. FIG. 4G is a partial enlarged view of E1region of the backlight assembly shown in FIG. 4F, and FIG. 4H is apartial enlarged view of E2 region of the backlight assembly shown inFIG. 4F. For example, the backlight assembly in the embodiment of thepresent disclosure includes a first sub-optical film 3101 and a secondmiddle frame 320. Here, the second middle frame 320 is a supportingframe which plays a role of supporting, and can also be called asupporting frame. The second middle frame 320 includes a secondsupporting portion having a second supporting surface facing the firstsub-optical film 3101 to support the first sub-optical film 3101. Asshown in FIG. 4C to FIG. 4H, the second supporting portion 321 includesa plurality of rims 3202, and the first sub-optical film 3101 includes aplurality of first edge portions. At least one rim 3202 of the secondsupporting portion 321 includes a first positioning groove 32100 and atleast one second positioning groove 3220. At least one first edgeportion of the first sub-optical film 3101 includes a first positioningportion 0110 and at least one second positioning portion 0120. The firstpositioning portion 0110 is located in the first positioning groove32100, and each second positioning portion 0120 is located in thecorresponding second positioning groove 3220 so that the firstsub-optical film 3101 is fixed on the second supporting portion. Forexample, each rim 3202 of the second supporting portion includes a firstpositioning groove 32100 and at least one second positioning groove3220, and each first edge portion of the first sub-optical film 3101includes a first positioning portion 0110 and at least one secondpositioning portion 0120.

For example, the second middle frame can be a structural member forsupporting the display module, which is used for accommodating andsupporting the optical film, a light bar (a light plate), a reflectivesheet and other elements. For example, the second middle frame may alsobe one of the structural components only supporting the optical film.For example, the second middle frame can be made of metal or plastic.

In a normal temperature environment, in the second positioning grooves3220 located on the same rim, there is a gap between two sides of thecorresponding second positioning portion which are close to two innersides of each second positioning groove in the extending direction ofthe rim. For example, in each rim, there may or may not be a gap betweensides of the first positioning groove opposite to each other in theextending direction of the rim and sides of the correspondingpositioning portion opposite to each other in the extending direction ofthe rim. When there is a gap between the sides of the first positioninggroove and the first positioning part, the sides of each positioninggroove opposite to each other in the extending direction of the rim andthe sides of the corresponding positioning portion opposite to eachother in the extending direction of the rim are not in contact with eachother.

The normal temperature environment in the embodiment of the presentdisclosure means that the ambient temperature of the backlight assemblyis in a range of 0˜40° C., such as 10˜30° C., such as 25° C. The secondsupporting portion includes a plurality of rims 3202 connected end toend to form a closed polygon. The embodiment of the present disclosuretakes four rims as an example, and the plurality of rims 3202 form arectangle, but is not limited thereto. The number of the rims can alsobe three or more, and the embodiment of the present disclosure is notlimited thereto.

For example, as shown in FIG. 4C to FIG. 4H, the embodiment of thepresent disclosure takes the backlight assembly as a curved surfacebacklight assembly as an example, in which at least one rim of the firstsupporting portion is an arc rim, and the projection of one of the arcrims on the XZ plane is a straight line and extends along the Xdirection. The first positioning groove 32100 located on the rimincludes two inner sides opposite to each other in the X direction, andthe first positioning portion 0110 is located between the two innersides, and there are intervals A1 and A2 between the two sides of thefirst positioning portion 0110 and the two inner sides respectively. Thesecond positioning groove 3220 on the rim also includes two inner sidesopposite to each other in the X direction, and the second positioningportion 0120 is located between the two inner sides, and there areintervals B1 and B2 between the two sides of the second positioningportion 0120 and the two inner sides, respectively. In the normaltemperature environment, there are two intervals between eachpositioning portion and the corresponding positioning groove in the Xdirection, one of which provides an expansion space for the firstsub-optical film and the other provides a contraction space for thefirst sub-optical film. Thus, when the backlight assembly provided bythe embodiment of the present disclosure is in a high temperatureenvironment (for example, 50˜100° C.) or a low temperature environment(for example, 0˜40° C.), there is an enough expansion space or an enoughcontraction space between the positioning portion of the firstsub-optical film and the corresponding positioning groove of the firstmiddle frame, thus preventing the first sub-optical film from beingwrinkled due to the obstruction of the first middle frame duringexpansion or contraction.

For example, in the normal temperature environment, the sizes of the twointervals reserved between each positioning portion and thecorresponding positioning groove can be the same or different, and thesize relationship between the two intervals can be determined accordingto the expansion and contraction amount of the first sub-optical film ina high temperature environment or a low temperature environment. Forexample, in a case where the backlight assembly provided by theembodiment of the disclosure is applied to a vehicle-mounted displaydevice, the temperature range of the vehicle-mounted environment can be−40˜95° C. Taking the temperature of the normal temperature environmentof 25° C. as an example, a low temperature difference between the lowesttemperature and the normal temperature is 65° C., and a high temperaturedifference between the highest temperature and the normal temperature is70° C. At this time, a width of the interval providing the expansionspace for the first sub-optical film is greater than a width of theinterval providing the contraction space for the first sub-optical film.For example, the width of the interval providing the expansion space forthe first sub-optical film is 0.1˜0.4 microns greater than the width ofthe interval providing the contraction space for the first sub-opticalfilm. For example, in order to facilitate manufacturing, the width ofthe interval providing the expansion space for the first sub-opticalfilm may be equal to the width of the interval providing the contractionspace for the first sub-optical film.

Upon the backlight assembly provided by the embodiment of the presentdisclosure being in different temperature environments, the widths ofthe two intervals between the positioning grooves and the correspondingpositioning portions will change to a certain extent. For example, theinterval providing the expansion space for the first sub-optical filmmay change to 0 upon the backlight assembly being in a high temperatureenvironment, or the interval providing the contraction space for thefirst sub-optical film may change to 0 upon the backlight assembly beingin a low temperature environment. Therefore, the widths of the twointervals between each positioning groove and the correspondingpositioning portion are based on a case that the backlight assembly isin the normal temperature environment.

As shown in FIG. 4C to FIG. 4H, upon the backlight assembly provided bythe embodiment of the present disclosure being in the normal temperatureenvironment, in the first positioning groove 32100 and the secondpositioning groove 3220 located on the same rim, a sum of sizes of thetwo intervals between the two opposite sides of the first positioningportion 0110 and two opposite sides of the first positioning groove32100 in the extending direction of the rim is the first space S1, and asum of sizes of the two opposite sides of each second positioningportion 0120 and two opposite sides of the corresponding secondpositioning groove 3220 in the extending direction of the rim is thesecond space S2. That is, the difference between the sizes of the firstpositioning groove 32100 and the first positioning portion 0110 in theextending direction of the rim is the first space S1, and the differencebetween the sizes of each second positioning groove 3220 and thecorresponding second positioning portion 0120 in the extending directionof the rim is the second space S2. The first space S1 is smaller thanthe second space S2.

For example, as shown in FIG. 4F to FIG. 4H, the sum of the sizes of theinterval A1 and the interval A2 between the first positioning groove32100 and the corresponding first positioning portion 0110 in theextending direction of the rim where the first positioning groove 32100is located is the first space S1; the sum of the sizes of the intervalB1 and the interval B2 between the second positioning groove 3220 andthe corresponding second positioning portion 0120 in the extendingdirection of the rim where the second positioning groove 3220 is locatedis the second space S2, and the first space S1 is smaller than thesecond space S2. Thus, the first positioning portion 0110 is an accuratepositioning portion, and the first positioning groove 32100 is anaccurate positioning groove, and the accurate positioning of the firstsub-optical film is realized by the cooperation of the accuratepositioning portion and the accurate positioning groove. The secondpositioning portion 0120 is a rough positioning portion, and the secondpositioning groove 3220 is a rough positioning groove. The roughpositioning of the first sub-optical film is realized by the cooperationof the rough positioning portion and the rough positioning groove.

The accurate positioning in the embodiment of the present disclosurerefers to only considering the manufacturing tolerance of the accuratepositioning portion and the accurate positioning groove, and themanufacturing tolerance is a tolerance that exists reasonably in orderto facilitate the installation of the accurate positioning portion intothe accurate positioning groove. For example, in actual products, thecutting tolerance range of the accurate positioning portion is in arange of 0.05˜0.1 mm, and the manufacturing tolerance range of theaccurate positioning groove is in a range of 0.05˜0.15 mm. For example,the widths of the interval A1 and the interval A2 between the accuratepositioning portion and the accurate positioning groove may both be 0.18mm, and then the first space S1 may be 0.36 mm. For example, the widthsof the interval A1 and the interval A2 may be the widths of thebacklight assembly upon it being in the normal temperature environment.In the case where the backlight assembly is in a vehicle-mountedenvironment and the backlight assembly is no longer in the normaltemperature environment, the widths of the interval A1 and the intervalA2 may change, but the first space S1 remains basically unchanged.

The accurate positioning in the embodiment of the present disclosurerefers to that the manufacturing tolerance and assembly tolerance of theaccurate positioning portion and the accurate positioning groove shouldbe considered without considering the deformation size affected by thetemperature and humidity, so that the relative displacement of theoptical film and the second middle frame can be limited in at least onedirection after the accurate positioning portion and the accuratepositioning groove are installed and fixed, so that the backlightassembly of a display device can meet the vibration reliability in acertain use scene, such as a vehicle-mounted display device. It shouldbe noted that those skilled in the art know that the existence ofaccurate positioning does not make the diaphragm completely idealwithout relative displacement.

The rough positioning in the embodiment of the present disclosure refersto considering the manufacturing tolerances and assembly tolerances ofthe rough positioning portion and the rough positioning groove, and thedeformation size of materials affected by temperature and humidity, sothat the rough positioning portion and the rough positioning groove canhave a certain relative displacement in at least one direction afterbeing fixed. In order to realize rough positioning, that is, to allowthe rough positioning portion and the rough positioning groove to moverelatively in at least one direction, the difference between the size ofthe rough positioning portion and the size of the rough positioninggroove is set to be greater than that between the size of the roughpositioning portion and the size of the rough positioning groove. Forexample, the widths of the interval B1 and the interval B2 between therough positioning portion and the rough positioning groove can both be 2mm, and the second space S2 can be 4 mm.

In the embodiment of the present disclosure, the combination of theaccurate positioning and the rough positioning is adopted between thefirst sub-optical film and the second middle frame, which can not onlyensure the fixation of the first sub-optical film and the second middleframe, but also ensure that the first sub-optical film is not prone towrinkle in the high temperature and high humidity environment, and doesnot affect normal display.

For example, as shown in FIG. 4C to FIG. 4H, the first sub-optical film3101 includes a plurality of outline edges corresponding to theplurality of rims 3202 of the second supporting portion 321, and theplurality of rims of the second supporting portion 321 support aplurality of first edge portions respectively. The embodiment of thepresent disclosure takes an example that the first sub-optical film 3101includes four outline edges surrounding to form the first sub-opticalfilm with a substantially rectangular shape, but is not limited thereto.The number of the outline edges can also be 3 or more, as long as therims of the second middle frame correspond to the outline edges of thefirst sub-optical film one by one, which is not limited by theembodiment of the present disclosure.

For example, as shown in FIG. 4C to FIG. 4H, a plurality of outlineedges of the first sub-optical film 3101 include a first sub-edgeportion 0101 extending along a first direction and a second sub-edgeportion 0102 extending along a second direction, and a length of thefirst sub-edge portion 0101 is greater than that of the second sub-edgeportion 0102. The first direction and the second direction in theembodiments of the present disclosure can be interchanged. In theembodiment of the present disclosure, taking the shape of the firstsub-optical film as a rectangle as an example, and then the firstsub-edge portion is a long side and the second sub-edge portion is ashort side.

For example, in a case where the backlight assembly provided by theembodiment of the present disclosure is applied to a display device witha large-size (for example, 20 inches or more), the length of the longside is not less than 400 mm, and the length of the short side is notless than 200 mm In the embodiment of the present disclosure, taking therim supporting the first sub-edge portion is a curved rim, such as anarc rim as an example, the second supporting surface forms a curvedsurface, and the backlight assembly is a curved surface backlightassembly. At this time, the rim supporting the second sub-edge portionmay be an arc rim or a straight rim. However, the embodiment of thepresent disclosure is not limited thereto, and the rim supporting thefirst sub-edge portion can also be a rim extending along a straightline, so that the second supporting surface of the second supportingportion is a plane, and the backlight assembly is a non-curved surfacebacklight assembly.

The outline edge of the first sub-optical film in the embodiment of thepresent disclosure may be a straight edge, a curved edge or a brokenline edge. For example, as shown in FIG. 4D, upon the outline edge ofthe first sub-optical film provided by the embodiment of the presentdisclosure being a broken line edge, one outline edge will have ageneral extending direction, such as the first direction or the seconddirection. At least one of the first sub-edge portion extending in thefirst direction and the second sub-edge portion extending in the seconddirection in the embodiment of the present disclosure is an arc-shapededge. For example, in an example of the embodiment of the presentdisclosure, the first sub-edge portion is an arc-shaped edge and thesecond sub-edge portion is a straight edge. In a case where the firstsub-edge portion is an arc-shaped side, the extending direction of thefirst sub-edge portion is also an arc-shaped extending direction. Atthis time, the above-mentioned first space may refer to the sum of thesizes of the two intervals between the two sides of the firstpositioning portion and the first positioning groove in the arcextending direction. Of course, upon the curvature of the arc side beingsmall, the difference between sizes of the two intervals in the arcextending direction and the size of the two intervals in the X directionis small.

The above-mentioned and later-mentioned “approximately rectangular”means that four sides of the film layer are not standard four straightlines, for example, the four sides of the film layer are fourbroken-line outline edges, and the quadrilateral formed by the fouroutline edges is not a rectangle in strict sense, but an approximatelyrectangle with four broken-line edges.

For example, as shown in FIG. 4C to FIG. 4H, the at least one secondpositioning portion 0120 includes a plurality of second positioningportions 0120, and the first positioning portion 0110 and the pluralityof second positioning portions 0120 are located at the first sub-edgeportion 0101. Therefore, the first positioning portion and the secondpositioning portion respectively realize the accurate positioning andrough positioning of the first sub-edge portion and the correspondingrim.

For example, as shown in FIG. 4C to FIG. 4H, the first positioningportion 0110 located on the first sub-edge portion 0101 is approximatelylocated at the midpoint of the first sub-edge portion 0101, and theplurality of second positioning portions 0120 located on the firstsub-edge portion 0101 are distributed on both sides of the firstpositioning portion 0110. The embodiment of the present disclosure takesthe number of the first positioning portions located on the firstsub-edge portion of one as an example, but is not limited thereto. Inthe embodiment of the disclosure, the plurality of second positioningportions located on the long side of the first sub-optical film are aplurality of rough positioning portions, and the accurate positioningportion is roughly disposed at the midpoint of the long side of thefirst sub-optical film, and the plurality of rough positioning portionsare distributed on both sides of the accurate positioning portion, sothat the first sub-optical film can expand to the left and right sides(taking the X direction as an example to the right) with the accuratepositioning portion as the center in the high temperature environment;or parts of the first sub-optical film located at both sides of theaccurate positioning portion shrink towards the middle in the lowtemperature environment. Therefore, the size change of the long side ofthe first sub-optical film when expanding or contracting can beminimized.

For example, as shown in FIG. 4C to FIG. 4H, in the first direction, thenumber of second positioning portions 0120 on both sides of the firstpositioning portion 0110 is equal, and the plurality of secondpositioning portions 0120 on both sides of the first positioning portion0110 are symmetrically distributed with the first positioning portion0110 as the center. Therefore, it is possible to ensure that the longside of the first sub-optical film expands or contracts symmetrically atthe high temperature or the low temperature, so as to facilitate thesetting of the relative positional relationship between the firstsub-optical film and the second middle frame. In the embodiment shown inFIG. 4D, taking the vertical placement of the first sub-optical film asan example, the direction indicated by the arrow in the Z direction isupward with the ground as a reference. At this time, the first sub-edgeportion is horizontally disposed and the second sub-edge portion isvertically disposed.

The embodiment of the present disclosure is not limited thereto. Forexample, FIG. 4E is a schematic plan view of the first sub-optical filmprovided by another example of the embodiment of the present disclosure.As shown in FIG. 4E, different from the optical film shown in FIG. 4D, aplurality of second positioning portions 0120 are located on the sameside of the first positioning portions 0110 on the first sub-edgeportion 0101. In the example shown in FIG. 4E, taking the verticalplacement of the first sub-optical film as an example, the directionindicated by the arrow in the X direction is upward with the ground as areference. At this time, the first sub-edge portion is verticallyarranged and the second sub-edge portion is horizontally arranged. Itshould be noted that the example shown in FIG. 4E differs from the firstsub-optical film in the example shown in FIG. 4D only in thedistribution positions of the first positioning portion and the secondpositioning portion, that is, the distribution position relationshipbetween the accurate positioning portion and the rough positioningportion is different, and other features of the first sub-optical filmshown in FIG. 4D described later are also included in the firstsub-optical film shown in FIG. 4E.

For example, as shown in FIG. 4E, the first positioning portion 0110 isdisposed within a range of ⅓ of the length of the first sub-edge portionclose to one end (for example, the upper end, the direction indicated bythe arrow in the X direction is upward relatively to the ground) of thefirst sub-edge portion 0101, and at least one second positioning portion0120 includes a plurality of second positioning portions 0120 disposedbetween the first positioning portion 0110 and the other end (lower end)of the first sub-edge portion 0101.

For example, in the normal temperature environment, a plurality ofsecond spaces corresponding to the plurality of second positioningportions 0120 gradually increase from the direction close to the firstpositioning portion 0110 to away from the first positioning portion0110, so that different and sufficient intervals can be reserved betweenthe positioning portions and the positioning grooves at variouspositions. Therefore, it can not only ensure that each position of thefirst sub-optical film will not wrinkle when expanding or contractingdue to temperature change in the vehicle-mounted environment, but alsoprevent waste of space and influence on the fixing of the firstsub-optical film and the second middle frame by the accurate design ofthe size of the space.

For example, as shown in FIG. 4C to FIG. 4H, at least one secondpositioning groove 3220 includes a plurality of second positioninggrooves 3220, which are arranged in one-to-one correspondence with theplurality of second positioning portions 0120 located on the firstsub-edge portion 0101, and each second positioning portion 0120 islocated in each second positioning groove 3220. In the normaltemperature environment, the sum of the sizes of the interval B1 and theinterval B2 between each second positioning portion 0120 and thecorresponding second positioning groove 3220 in the first direction isthe second space S2, and the second spaces S2 corresponding to thesecond positioning portions 0120 located on the first sub-edge portion0101 gradually increase in the direction from the midpoint of the firstsub-edge portion 0101 to the two end points. In a case where the firstsub-edge portion is an arc-shaped side, the above-mentioned second spacecan refer to the sum of the sizes of two intervals between the two sidesof the second positioning portion and the corresponding secondpositioning grooves in the extending direction of the arc-shaped side.

For example, one of the interval B1 and the interval B2 between eachsecond positioning portion 0120 and the corresponding second positioninggroove 3220 is an interval for providing the expansion space for thefirst sub-optical film 3101 (i.e., an expansion space), and the other isan interval for providing the contraction space for the firstsub-optical film 3101 (i.e., a contraction space). This disclosureschematically shows that the second space between each secondpositioning portion and the corresponding second positioning grooveincludes the expansion space and the contraction space, but is notlimited thereto. The second space between each second positioningportion and the corresponding second positioning groove can also includeone of the expansion space and the contraction space, that is, onlyexpansion space or contraction space.

For example, an example of the embodiment of the present disclosure isdescribed by taking the interval B1 as the interval for providing theexpansion space for the first sub-optical film 3101, and the interval B2as the interval for providing the contraction space for the firstsub-optical film 3101 as an example. In the embodiment of thisdisclosure, the temperature range of the vehicle-mounted environment inwhich the backlight assembly is applied is −40° C.˜95° C., and thetemperature of the normal temperature environment is 25° C., so thetemperature difference of the vehicle-mounted environment in which thebacklight assembly is located is 65° C. from the normal temperature tothe lowest temperature and 70° C. from the normal temperature to thehighest temperature. The value of the expansion design interval B1 ofthe first sub-optical film 3101 is greater than the expansion requiredgap1 of the first sub-optical film 3101, and the expansion required gap1satisfies gap1=ΔT1*L*CET1. In the above relation, ΔT1 represents thehigh temperature difference of the vehicle-mounted environment where thefirst sub-optical film 3101 is located, L represents the distancebetween the midpoint of the second positioning portion 0120 and themidpoint of the first positioning portion 0110, and CET1 represents thethermal expansion coefficient of the first sub-optical film 3101 in thefirst direction. The expansion required gap1 corresponding to theinterval B1 of the second positioning portion 0120 at the E2 regionshown in FIG. 4F satisfies gap1=70*L*CET1.

The thermal expansion coefficient CET1 of the first sub-optical film3101 in the first direction is related to the temperature range of thefirst sub-optical film 3101. For example, the value of the thermalexpansion coefficient CET1 of the first sub-optical film 3101 in atemperature range of 75° C.˜95° C. is greater than that of the firstsub-optical film 3101 in a temperature range of 50° C.˜75° C., and thevalue of thermal expansion coefficient CET1 of the first sub-opticalfilm 3101 in a temperature range of 50° C.˜75° C. is greater than thatof the first sub-optical film 3101 in a temperature range of 25° C.˜50°C.

In addition, the thermal expansion coefficient on the first sub-edgeportion (long side) of the first sub-optical film in the embodiment ofthe present disclosure is smaller than that on the second sub-edgeportion (short side), so that the expansion required gap of the firstsub-optical film on the first sub-edge portion can be reduced.

For example, for a backlight assembly with high brightness requirements,a polarizer brightness enhancement film can be used; for a backlightassembly with conventional brightness requirements, an ordinarybrightness enhancement film and a diffusion film can be used.

For example, the first sub-optical film 3101 may include at least one ofa first diffuser sheet, a prism layer and a second diffuser sheet. Forexample, a material of the first diffuser sheet may include polyethyleneterephthalate (PET), polycarbonate, or the like.

The thermal expansion coefficients of single-layer films such as anordinary brightness enhancement film and a diffuser film can be 3.5*10⁻⁵cm/(cm*° C.) in the short side direction and 3.0*10⁻⁵ cm/(cm*° C.) inthe long side direction. Amount of shrinkage in the short side directionis about 0.5%, and amount of shrinkage in the long side direction isabout 0.2%. The above-mentioned single-layer films such as the ordinarybrightness enhancement film and the diffusion film have differentexpansion coefficients in two different stretching directions (forexample, TD direction or MD direction), and the expansion coefficientand contraction coefficient in MD direction are small, so the expansionand contraction amount in TD direction is greater than that in MDdirection. Generally, when designing a product, the long side isdesigned in the MD direction, which can minimize the expansion andcontraction space of the long side.

The expansion coefficient of single-layer films such as the ordinarybrightness enhancement film and the diffuser film is determined by thematerial (such as polymethyl methacrylate PMMA or polycarbonate PC), thestretching direction of the material (such as TD direction or MDdirection) and the temperature range.

The designed interval for contraction B2 of the first sub-optical film3101 is greater than the contraction required gap2 of the firstsub-optical film 3101, and the contraction required gap2 satisfiesgap2=ΔT2*L*CET1. ΔT2 in the above relation represents the lowtemperature difference of the vehicle-mounted environment where thefirst sub-optical film 3101 is located. Then the contraction requiredgap2 corresponding to the interval B2 of the second positioning portion0120 at the E2 region shown in FIG. 4F satisfies gap2=65*L*CET1.

The above-mentioned interval B1 (interval B2) is not only related to theexpansion required gap1 (contraction required gap2), but also related tothe cutting tolerance (DBEF) of the first sub-optical film 3101 and theinjection molding tolerance (DMF) of the second middle frame 320. Forexample, the cutting tolerance of the first sub-optical film 3101depends on the tolerance zone corresponding to the position size of theinterval B1 (interval B2) and the injection molding tolerance of thesecond middle frame 320 depends on the tolerance zone corresponding tothe position size of the interval B1 (interval B2). The tolerance zonerefers to an area defined by two straight lines representing the upperdeviation and the lower deviation or the maximum limit size and theminimum limit size in the tolerance zone diagram, which can also becalled the size tolerance zone.

For example, taking an example that the width of the interval providingthe contraction space (the contraction interval) for the firstsub-optical film is equal to the width of the interval providing theexpansion space (the expansion interval) for the first sub-optical film,the cutting tolerance of the first sub-optical film 3101 at the firstpositioning portion 0110 is approximately 0.05 mm, the injection moldingtolerance of the second middle frame 320 corresponding to the firstpositioning portion is approximately 0.05 mm, and the expansion requiredgap1 is approximately 0.07 mm, and then the interval A1 and the intervalA2 should be not less than 0.17 mm, for example, the interval A1 and theinterval A2 may both be 0.18 mm, and the first space may be 0.36 mm.

For example, a distance between a center of the second positioningportion 0120 in the E2 region and a center of the first positioningportion 0110 is L1, and L1 is approximately 172 mm. At a position of thesecond positioning portion 0120 in the E2 region, the cutting toleranceof the first sub-optical film 3101 is approximately 0.1 mm, theinjection molding tolerance of the second middle frame 320 isapproximately 0.15 mm, and the expansion required gap1 is approximately0.98 mm, and then the interval B1 and the interval B2 should be not lessthan 1.2 mm, for example, the interval B1 and the interval B2 can be 2mm, and the second space can be 4 mm.

For example, a distance between a center of the second positioningportion 0120 in the E3 region and the center of the first positioningportion 0110 is L2, and L2 is approximately 343 mm. At the position ofthe second positioning portion 0120 in the E3 region, the cuttingtolerance of the first sub-optical film 3101 is approximately 0.15 mm,the injection molding tolerance of the second middle frame 320 isapproximately 0.15 mm, the expansion required gap1 is approximately 1.95mm, and then the interval for providing the expansion spacecorresponding to the second positioning portion 0120 in the E3 regionshould not be less than 2.25 mm, for example, the expansion interval inthe E3 region can be 2.5 mm. Upon the contraction interval in the E3region being 2.5 mm, the second space can be 5 mm.

For example, a distance between a center of the second positioningportion 0120 in the E4 region and the center of the first positioningportion 0110 is L3, and L3 is approximately 540 mm. At the position ofthe second positioning portion 0120 in the E4 region, the cuttingtolerance of the first sub-optical film 3101 is approximately 0.15 mm,the injection molding tolerance of the second middle frame 320 isapproximately 0.15 mm, the expansion required gap1 is approximately 3.06mm, and then the interval for providing the expansion spacecorresponding to the second positioning portion 0120 in the E3 regionshould be no less than 3.36 mm, for example, 3.4 mm, and the secondspace can be 6.8 mm.

With the increase of the distances between the second positioningportions and the first positioning portion, the required gaps forproviding the expansion space and the contraction space corresponding tothe second positioning portions gradually increase. For example, thesecond space between each second positioning portion and thecorresponding second positioning groove includes the expansion space andthe contraction space. In the normal temperature environment, in thedirection from the midpoint of the first sub-edge portion to the endpoints at both sides, the expansion spaces corresponding to the secondpositioning portions gradually increase, and the contraction spacescorresponding to the second positioning portions gradually increase.Therefore, in the embodiment of the disclosure, in the direction fromthe midpoint of the first sub-edge to the end points at both sides, aplurality of second spaces corresponding to the plurality of secondpositioning portions on the first sub-edge portion are graduallyincreased, so that different and sufficient intervals can be reservedbetween the positioning portions and the positioning grooves at variouspositions, and furthermore, various positions of the first sub-opticalfilm can be guaranteed not to wrinkle when expanding or contracting dueto temperature changes in the vehicle-mounted environment, and spacewaste can be prevented by the accurate design of the size of the gap,thus preventing the influence on the fixing of the first sub-opticalfilm and the second middle frame.

For example, in an example of the embodiment of the present disclosure,the backlight assembly is a curved surface backlight assembly, and therim used for supporting the first sub-edge portion (the long side) ofthe first sub-optical film 3101 in the second supporting portion of thesecond middle frame 320 is a curved rim, for example, an arc rim, sothat the first sub-optical film 3101 is formed into a curved structure.At this time, the extending direction of the first sub-edge portion is acurved extending direction, which is different from the X directionshown in the figure. When applied to the curved surface backlightassembly in the vehicle-mounted environment with temperature rangingfrom −40° C. to 100° C., humidity up to 90%, and single use time over1000 hours, different expansion and contraction sizes will occur atdifferent positions of the first sub-optical film. However, the generalstructure in which the first sub-optical film and the second middleframe are simply fixed by rough positioning and the gap between thefirst sub-optical film and the second middle frame is fixed at thecoarse positioning position cannot guarantee the overall radianuniformity when the first sub-optical film is in a curved state,resulting in the first sub-optical film being prone to wrinkles such aslocal bulging.

In the embodiment of the present disclosure, in the arc direction of thebacklight assembly, the first sub-optical film and the second middleframe adopt a combination of accurate positioning and rough positioningto match with the way that different and sufficient intervals arereserved between the plurality of positioning portions and correspondingpositioning grooves, which can not only ensure that the firstsub-optical film is in a good fixed state under long-term severevibration conditions, but also meet the requirements of the expansionspace and the contraction space of different positions in the firstsub-optical film under long-term high-temperature and high-humidityvehicle-mounted environment.

For example, as shown in FIG. 4C to FIG. 4H, the first positioningportion 0110 on the first sub-edge portion 0101 includes a firstprotruding portion 0111, and each of the plurality of second positioningportions 0120 on the first sub-edge portion 0101 includes a secondprotruding portion 0121. In the embodiment of the present disclosure,the outline edges (first sub-edge portions) where the first protrudingportion 0111 and the second protruding portion 0121 are located includeprotruding portions and straight lines (that is, connecting lines 0130)between adjacent protruding portions. Therefore, a plurality ofprotruding portions and a plurality of connecting lines are connectedend to end to form a zigzag outline edge.

For example, as shown in FIG. 4C to FIG. 4H, the middle of the secondprotruding portion 0121 includes an opening 12, and the first protrudingportion 0111 does not include an opening. Each of the plurality ofsecond positioning grooves 3220 includes a boss 3221, and the opening 12of the second protruding portion 0121 is configured to be sleeved on theboss 3221 to fix the first sub-optical film 3101 and the second middleframe 320.

For example, as shown in FIG. 4C to FIG. 4H, compared with the generalway that the first sub-optical film only includes a hanger loop with anopening to fix with a structural member, the embodiment of the presentdisclosure uses a protruding portion without an opening (e.g., a lug) asan accurate positioning portion and a protruding portion with an opening(e.g., a hanger loop) as a rough positioning portion, which can realizethe combination of accurate positioning and rough positioning of thefirst sub-optical film and fix the first sub-optical film on the secondmiddle frame more stably. In the embodiment of the present disclosure,the protruding portion as the accurate positioning portion can be asolid structure without an opening, so that the structural strength ofthe accurate positioning portion can be increased.

For example, as shown in FIG. 3F, FIG. 4C to FIG. 4H, in the normaltemperature environment, the size of each boss 3221 in the firstdirection is smaller than that of the corresponding opening 12 in thefirst direction, so that there is an interval between two sides of eachboss and two inner sides of the corresponding opening in the firstdirection. That is, the opposite sides of each boss in the firstdirection are not in contact with the opposite sides of thecorresponding opening in the first direction.

For example, there are two intervals between the boss 3221 and theopening 12, namely interval C1 and interval C2. When the first sub-edgeportion is an arc-shaped side, the size of the interval C1 (or theinterval C2) may refer to the size of the interval C1 (or the intervalC2) in the extending direction of the arc-shaped side. In the normaltemperature environment, one of the two intervals arranged between eachboss and the corresponding opening in the first direction provides anexpansion space for the first sub-optical film, and the other of the twointervals provides a contraction space for the first sub-optical film.For example, the size of the interval C1 in the first direction may be acontraction space, and the size of the interval C2 in the firstdirection may be an expansion space. Thus, when the backlight assemblyprovided by the embodiment of the present disclosure is in a hightemperature environment (e.g., 50˜100° C.) or a low temperatureenvironment (e.g., 0˜40° C.), there is enough expansion interval orcontraction interval between the opening of the first sub-optical filmand the boss of the second middle frame, thus preventing the firstsub-optical film from being wrinkled due to the obstruction of thesecond middle frame during expansion or contraction.

For example, in the normal temperature environment, the sizes of the twointervals reserved between each boss and the two inner sides of thecorresponding opening can be the same or different, and the sizerelationship between the two intervals can be determined according tothe expansion and contraction size of the first sub-optical film in hightemperature or low temperature environment. For example, in order tofacilitate fabrication, the width of the interval providing expansionspace for the first sub-optical film among the above two intervalsbetween each opening and the corresponding boss may be equal to thewidth of the interval providing contraction space for the firstsub-optical film.

As the widths of the two intervals between each opening and thecorresponding boss will change to some extent when the backlightassembly provided by the embodiment of the present disclosure is indifferent temperature environments, for example, the gap providingexpansion space for the first sub-optical film may change to 0 when thebacklight assembly is in a high temperature environment, or the gapproviding contraction space for the first sub-optical film may change to0 when the backlight assembly is in a low temperature environment.Therefore, the widths of the two intervals between each opening and thecorresponding boss are based on the normal temperature environment ofthe backlight assembly.

For example, as shown in FIG. 4C to FIG. 4H, the sum of the sizes of theinterval C1 and the interval C2 between the opening 12 and the sides ofthe boss 3221 close to each other in the first direction is a thirdspace S3, that is, the difference between the size of the opening andthe size of the boss in the first direction is the third space, and thethird space S3 is greater than the first space S1. In the direction fromthe midpoint of the first sub-edge portion 0101 to the end points atboth sides, the third spaces corresponding to the second positioningportions gradually increase.

For example, in an example of the embodiment of the present disclosure,the interval C2 is used to provide expansion space for the firstsub-optical film 3101, and the interval C1 is used to providecontraction space for the first sub-optical film 3101, so the size ofthe interval C2 can be the same as that of the interval B1, that is, thecalculation relation of the interval C2 is the same as that of theinterval B1. The size of the interval C1 may be the same as that of theinterval B2, that is, the calculation relation of the interval C1 is thesame as that of the interval B2.

For example, the third space S3 may be equal to the second space S2 tofacilitate the design of the first sub-optical film.

For example, taking the temperature range of the vehicle-mountedenvironment in which the backlight assembly provided by the embodimentof the present disclosure is applied as −40° C.˜95° C., and thetemperature of the normal temperature environment as 25° C., thetemperature difference of the vehicle-mounted environment in which thebacklight assembly is located is 65° C. from the normal temperature tothe lowest temperature, and the temperature difference of thevehicle-mounted environment in which the backlight assembly is locatedis 70° C. from the normal temperature to the highest temperature. Forexample, taking a gap of a contraction space for the first sub-opticalfilm being equal to a gap of a expansion space for the first sub-opticalfilm as an example, the interval C1 and the interval C2 should be noless than 1.23 mm at the position of the second positioning portion 0120in the E2 region, for example, the interval C1 and the interval C2 canbe 2 mm, and the third space S3 can be 4 mm.

For example, at the position of the second positioning portion 0120 inthe E3 region, the gap corresponding to the second positioning portion0120 for providing expansion space should be not less than 2.25 mm, forexample, 2.5 mm, and the third space can be 5 mm. For example, at theposition of the second positioning portion 0120 in the E4 region, thegap corresponding to the second positioning portion 0120 for providingexpansion space should be not less than 3.36 mm, for example, 3.4 mm,and the third space can be 6.8 mm With the increase of the distancesbetween the second positioning portions and the first positioningportion, the required spaces between the second positioning portions forproviding expansion space and contraction space gradually increase.Therefore, in the embodiment of the disclosure, in the direction thatthe midpoint of the first sub-edge portion points to the end points ofboth sides, a plurality of third spaces corresponding to the pluralityof second positioning portions on the first sub-edge portion aregradually increased, so that different and sufficient intervals can bereserved between bosses and openings at various positions, and further,various positions of the first sub-optical film can be guaranteed not towrinkle when expanding or contracting due to temperature changes in thevehicle-mounted environment, and space waste can be prevented by theaccurate design of the sizes of the gaps, so as to prevent the influenceon the fixing of the first sub-optical film and the second middle frame.

For example, FIG. 4I is a partial enlarged view of E5 region of thebacklight assembly shown in FIG. 4F, and FIG. 4J is a partial enlargedview of E6 region of the backlight assembly shown in FIG. 4F. As shownin FIG. 4C to FIG. 4J, the first edge portion includes a thirdpositioning portion 1100 and at least one fourth positioning portion1200 located at the second sub-edge portion 0102, and the fourthpositioning portion 1200 is disposed at one side of the thirdpositioning portion 1100 in the second direction. The rim of the firstsupporting portion also includes a third positioning groove 2100 and atleast one fourth positioning groove 2200, the third positioning portion1100 is located in the third positioning groove 2100, and each fourthpositioning portion 1200 is located in the corresponding fourthpositioning groove 2200, and the fourth positioning portion 1200 islocated at one side of the third positioning portion 1100 in the seconddirection.

In the normal temperature environment, the sides of each fourthpositioning groove 2200 opposite to each other in the second directionare not in contact with the sides of the corresponding fourthpositioning portion 1200 opposite to each other in the second direction,and the difference between the sizes of the third positioning groove2100 and the third positioning portion 1100 in the second direction issmaller than that of each fourth positioning groove 2200 and thecorresponding fourth positioning portion 1200 in the second direction.Therefore, the fourth positioning portion is a rough positioning portionand the fourth positioning groove is a rough positioning groove, and therough positioning of the first sub-optical film in the second directionis realized by the cooperation of the rough positioning portion and therough positioning groove.

For example, the embodiment of the present disclosure schematicallyshows that one third positioning portion and one fourth positioningportion are arranged on a second sub-edge portion, and at this time, thethird positioning portion and the fourth positioning portion can beroughly symmetrically distributed relative to the midpoint of the secondsub-edge portion. The embodiment is not limited thereto, one secondsub-edge portion can be provided with a plurality of fourth positioningportions, which are all located on the same side of the thirdpositioning portion, and the third positioning portion and the fourthpositioning portions are roughly evenly distributed on the secondsub-edge portion.

The embodiment of the present disclosure is not limited thereto. Whenthe number of the fourth positioning portions is more than one, theplurality of fourth positioning portions are all located on the sameside of the third positioning portion, and the size differences betweenrespective fourth positioning grooves and corresponding fourthpositioning portions in the second direction can gradually increase inthe direction from close to the third positioning portion to away fromthe third positioning portion. For example, the difference between thesizes of each fourth positioning groove and the corresponding fourthpositioning portion in the second direction may include at least one ofan expansion space and a contraction space. In the normal temperatureenvironment, in the direction from close to the third positioningportion to away from the third positioning portion, the expansiondistances corresponding to the fourth positioning portions graduallyincrease, and/or the contraction distances corresponding to the fourthpositioning portions gradually increase.

For example, as shown in FIG. 4C to FIG. 4J, the plurality of fourthpositioning grooves 2200 are arranged in one-to-one correspondence withthe fourth positioning portions 1200 on the second sub-edge portion0102, and the number of the fourth positioning grooves 2200 is the sameas that of the fourth positioning portions 1200, and each fourthpositioning portion 1200 is located in the corresponding fourthpositioning groove 2200.

For example, as shown in FIG. 4C to FIG. 4J, in the normal temperatureenvironment, there is an interval in the second direction between thetwo inner sides of the corresponding fourth positioning groove which areclose to the two sides of each fourth positioning portion on the secondsub-edge portion 0102. That is, the rough positioning portion in therough positioning groove does not contact with the rough positioninggroove in the second direction. For example, there may or may not be aninterval between the two inner sides of the corresponding thirdpositioning groove which are close to the two sides of each thirdpositioning portion in the second direction.

For example, as shown in FIG. 4I to FIG. 4J, taking one rim extending inthe Z direction among a plurality of rims 3202 as an example, the thirdpositioning groove 2100 on the rim includes two inner sides opposite toeach other in the Z direction, and the third positioning portion 1100 onthe second sub-edge portion 0102 is located between the two inner sides,and there are two intervals between the third positioning portion 1100and the two inner sides, namely an interval P1 and an interval P2. Theembodiment of the present disclosure is not limited thereto, and theremay be only an interval P2 between the third positioning portion 1100and the two inner sides of the third positioning groove 2100, that is,the size of the interval P1 may be 0.

For example, each fourth positioning groove 2200 on the rim alsoincludes two inner sides opposite to each other in the Z direction, andthe fourth positioning portion 1200 on the second sub-edge portion 0102is located between these two inner sides, and there are two intervalsbetween the fourth positioning portion 1200 and these two inner sides,namely an interval G1 and an interval G2. For example, a size of theinterval G1 in the second direction may be a contraction space, and asize of the interval G2 in the second direction may be an expansionspace.

For example, on the second sub-edge portion 0102, the sum of the sizesof the intervals between sides of each fourth positioning portion 1200and sides of the corresponding fourth positioning groove 2200 adjacentto the sides of each fourth positioning portion 1200 in the seconddirection is greater than the sum of the sizes of the intervals betweensides of the third positioning portion 1100 and sides of thecorresponding third positioning groove 2100 adjacent to the sides of thethird positioning portion 1100 in the second direction. For example, thesum of the interval P1 and the interval P2 between the third positioningportion 1100 on the second sub-edge portion 0102 and the correspondingthird positioning groove 2100 in the second direction is smaller thanthe sum of the interval G1 and the interval G2 between the fourthpositioning portion 1200 on the second sub-edge portion 0102 and thecorresponding fourth positioning groove 2200 in the second direction.

For example, as shown in FIG. 4D to FIG. 4H, the opening 12 of thesecond positioning portion 0120 on the first sub-edge portion close tothe third positioning portion 1100 may contact with or keep a smalldistance from a side of the boss 3221 away from the third positioningportion 1100 in the second direction, and a size of the interval P1between the side of the third positioning portion 1100 away from thefourth positioning portion 1200 and the corresponding side of the thirdpositioning groove 2100 may be small or even zero. The size of theinterval P1 between the side of the third positioning portion 1100 awayfrom the fourth positioning portion 1200 and the corresponding side ofthe third positioning groove 2100 is smaller than a size of the intervalP2 between the side of the third positioning portion 1100 close to thefourth positioning portion 1200 and the corresponding side of the thirdpositioning groove 2100 to realize accurate positioning of the firstsub-optical film in the second direction; sizes of an interval G1 and aninterval G2 between the two sides of the fourth positioning portion 1200and the corresponding fourth positioning groove 2200 are both greaterthan the size of the interval P1. Therefore, in the embodiment of thepresent disclosure, the first positioning portion and the thirdpositioning portion together serve as an accurate positioning portion,and the fourth positioning portion serves as a rough positioningportion. In the embodiment of the present disclosure, the combination ofaccurate positioning and rough positioning is adopted between the secondsub-edge portion of the first sub-optical film extending in the seconddirection and the rim of the second middle frame, which can not onlyensure the fixation of the first sub-optical film and the second middleframe, but also ensure that the first sub-optical film in hightemperature and high humidity environment is not easy to wrinkle in thesecond direction, and does not affect normal display.

In the embodiment of the present disclosure, under the condition thatthe size of the second sub-edge portion is small, one accuratepositioning portion and at least one rough positioning portion can bedisposed on the second sub-edge portion, which can make the firstsub-optical film expand to one side with the accurate positioningportion as the center in high temperature environment; or a part of thefirst sub-optical film located at one side of the accurate positioningportion shrinks toward the accurate positioning portion under a lowtemperature environment. Of course, the embodiments of the presentdisclosure are not limited thereto. In a case where the length of thesecond sub-edge portion is long and the number of rough positioningportions is large, the rough positioning portions can also bedistributed on both sides of the accurate positioning portions tominimize the size change of the second sub-edge portion of the firstsub-optical film when expanding or contracting.

For example, as shown in FIG. 2A, FIG. 4C, FIG. 4D and FIG. 4F to FIG.4J, taking the vertical placement of the first sub-optical film providedby the embodiment of the present disclosure as an example, the directionindicated by the arrow in the Z direction is upward with the ground as areference. At this time, the first sub-edge portion is horizontallydisposed and the second sub-edge portion is vertically disposed. Anexample of the embodiment of the present disclosure is described bytaking the interval P2 and the interval G2 as the intervals forproviding expansion space for the first sub-optical film 3101, and theinterval P1 and the interval G1 as the intervals for providingcontraction space for the first sub-optical film 3101 as an example fordescription. Taking the temperature range of the vehicle-mountedenvironment in which the backlight assembly provided by the embodimentof the disclosure is applied as −40° C.˜95° C., and the temperature ofthe normal temperature environment as 25° C., the temperature differenceof the vehicle-mounted environment in which the backlight assembly islocated is 65° C. from the normal temperature to the lowest temperature,and the temperature difference of the vehicle-mounted environment inwhich the backlight assembly is located is 70° C. from the normaltemperature to the highest temperature. The interval P2 of the firstsub-optical film 3101 is greater than the expansion demand gap3 of thefirst sub-optical film 3101, and the expansion demand gap3 satisfiesgap3=A T1*V1*CET2.

A T1 represents the high temperature difference of the vehicle-mountedenvironment where the first sub-optical film 3101 is located; as shownin FIG. 4D, V1 represents a distance between an edge of the thirdpositioning portion 1100 away from the fourth positioning portion 1200and a side of the protrusion of the first sub-edge portion 0101, whichis close to the third positioning portion 1100, away from the thirdpositioning portion 1100 in the second direction, and CET2 representsthe thermal expansion coefficient of the first sub-optical film 3101 inthe second direction. The expansion demand gap3 corresponding to theinterval P2 of the third positioning portion 1100 at the E5 positionshown in FIG. 4F satisfies the relational of gap3=70*V1*CET2.

The thermal expansion coefficient CET2 of the first sub-optical film3101 in the second direction is related to the temperature range of thefirst sub-optical film 3101. For example, the value of the thermalexpansion coefficient CET2 of the first sub-optical film 3101 at 75°C.˜95° C. is greater than that of the first sub-optical film 3101 at 50°C.˜75° C., and the value of thermal expansion coefficient CET2 of thefirst sub-optical film 3101 at 50° C.˜75° C. is greater than that of thefirst sub-optical film 3101 at 25° C.˜50° C. The interval P1 of thefirst sub-optical film 3101 is greater than the contraction requiredgap4 of the first sub-optical film 3101, and the contraction requiredgap4 satisfies gap4=ΔT2*V2*CET2.

ΔT2 in the above relational expression represents the low temperaturedifference of the vehicle-mounted environment where the firstsub-optical film 3101 is located, and V2 represents a distance betweenan edge of the third positioning portion 1100 close to the fourthpositioning portion 1200 and the edge of the protruding portion of thefirst sub-edge portion 0101 away from the third positioning portion 1100in the second direction, so that the contraction required gap4corresponding to the interval P1 of the third positioning portion 1100at the E5 position shown in FIG. 4F satisfies the relational ofexpression gap4=65*V2*CET2.

The interval G2 of the first sub-optical film 3101 is greater than theexpansion required gap5 of the first sub-optical film 3101, and theexpansion required gap5 satisfies gap5=ΔT1*V3*CET2. V3 represents adistance between the edge of the fourth positioning portion 1200 closeto the third positioning portion 1100 and the side of the protrudingportion of the first sub-edge portion 0101 away from the thirdpositioning portion 1100 in the second direction.

In the same way, the interval G1 of the first sub-optical film 3101 isgreater than the contraction required gap6 of the first sub-optical film3101, and the contraction required gap6 satisfies gap6=ΔT2*V4*CET2. V4represents a distance between the edge of the fourth positioning portion1200 away from the third positioning portion 1100 and the side of theprotruding portion of the first sub-edge portion 0101 (the firstsub-edge portion close to the third positioning portion) away from thethird positioning portion 1100 in the second direction.

The width of each interval is related to not only the expansion gap andthe contraction required gap, but also the cutting tolerance (DBEF) ofthe first sub-optical film 3101 and the injection molding tolerance(DMF) of the second middle frame 320. For example, the cutting toleranceof the first sub-optical film 3101 depends on the tolerance zonecorresponding to the position size of each interval, and the injectionmolding tolerance of the second middle frame 320 depends on thetolerance zone corresponding to the position size of each interval.

For example, at the position of an edge of the third positioning portion1100 away from the fourth positioning portion 1200, the cuttingtolerance of the first sub-optical film 3101 is approximately 0.2 mm,the injection molding tolerance of the second middle frame 320 isapproximately 0.15 mm, V1 is approximately 51 mm, and the contractiondemand gap is approximately 0.2 mm, so the interval P1 should be no lessthan 0.55 mm, for example, the interval P1 can be 0.6 mm as the accuratepositioning position.

For example, at the position of the edge of the third positioningportion 1100 close to the fourth positioning portion 1200, the cuttingtolerance of the first sub-optical film 3101 is approximately 0.2 mm,the injection molding tolerance of the second middle frame 320 isapproximately 0.15 mm, V2 is approximately 75 mm, and the expansionrequired gap is approximately 0.3 mm, so the interval P2 should be notless than 0.65 mm, for example, the interval P2 can be 1.5 mm.

For example, at the position of the edge of the fourth positioningportion 1200 close to the third positioning portion 1100, the cuttingtolerance of the first sub-optical film 3101 is approximately 0.2 mm,the injection molding tolerance of the second middle frame 320 isapproximately 0.15 mm, V3 is approximately 165 mm, and the contractionrequired gap is approximately 0.6 mm, so the interval G1 should be noless than 0.95 mm, for example, the interval G1 may be 1.5 mm.

For example, at the position of the edge of the fourth positioningportion 1200 away from of the third positioning portion 1100, thecutting tolerance of the first sub-optical film 3101 is approximately0.1 mm, the injection molding tolerance of the second middle frame 320is approximately 0.15 mm, V4 is approximately 188 mm, and the expansionrequired gap is approximately 0.79 mm, so the interval G2 should be notless than 1.04 mm, for example, the interval G2 can be 1.5 mm.

For example, as shown in FIG. 4C to FIG. 4J, the third positioningportion 1100 on the second sub-edge portion 0102 includes a thirdprotruding portion 0112, and the fourth positioning portion 1200 on thesecond sub-edge portion 0102 includes a fourth protruding portion 0122.In the embodiment of the present disclosure, the outline edges (secondsub-edge portions) where the third protruding portion 0112 and thefourth protruding portion 0122 are located include protruding portionsand linear connecting lines between adjacent protruding portions, sothat a plurality of protruding portions and connecting lines areconnected end to end to form a zigzag outline edge. In the embodiment ofthe present disclosure, the third protruding portion and the fourthprotruding portion are protruding portions without openings. Of course,the embodiment of the present disclosure is not limited thereto, and thefourth protruding portion may also be a protruding portion with anopening. At this time, the fourth positioning groove where the fourthprotruding portion is located needs to be provided with a bosscorresponding to the opening, so that the opening can be sleeved on theboss.

FIG. 4K is a partial enlarged view of E7 region of the backlightassembly shown in FIG. 4F, and FIG. 4L is a partial enlarged view of E8region of the backlight assembly shown in FIG. 4F. For example, as shownin FIG. 4C to FIG. 4L, taking the vertical placement of the firstsub-optical film provided by the embodiment of the present disclosure asan example, the direction indicated by the arrow in the Z direction isupward with the ground as a reference. At this time, a distance betweenthe opening 12 of the second protruding portion 0121 of the secondpositioning portion 0120 in the E2 region and an upper side of the boss3221 is 0. That is, the distance between the opening of the secondprotruding portion on the upper side of the first sub-optical film andthe upper side of the corresponding boss is 0, and the first sub-opticalfilm is hung on the protrusion, which supports the first sub-opticalfilm in Z direction.

For example, the interval I2 between the opening 12 of the secondprotruding portion 0121 of the second positioning portion 0120 in the E8region and the upper side of the boss 3221 is used to provide expansionspace for the first sub-optical film 3101 in the second direction, andthe interval I1 between the opening 12 of the second protruding portion0121 of the second positioning portion 0120 in the E8 region and thelower side of the boss 3221 is used to provide contraction space for thefirst sub-optical film 3101 in the second direction. The value of theinterval I2 can be calculated to be 1.35 mm, and the value of theinterval I1 can be calculated to be 0.83 mm according to references suchas the cutting tolerance (DBEF) of the first sub-optical film 3101 atthe position of the second positioning portion 0120 in the E8 region,the injection molding tolerance (DMF) of the second middle frame 320,the expansion coefficient of the first sub-optical film 3101, thechanging temperature difference of the environment where the backlightassembly is located, and a distance between a middle point of the secondpositioning portion 0120 in the E8 region and an edge of the secondpositioning portion 0120 in the E2 region away from the E8 region.

For example, as shown in FIG. 4C to FIG. 4L, a plurality of blockingwalls 3230 are further included around the second middle frame 320. Eachof the plurality of blocking walls 3230 includes two sub-blocking walls3231 arranged in the extending direction (the first direction or thesecond direction) of the rim where the blocking wall 3230 is located,and the first positioning groove 32100, the second positioning groove3220, the third positioning groove 2100 or the fourth positioning groove2200 are arranged between the two sub-blocking walls 3231. In theembodiment of the present disclosure, the relatively concave portionbetween two sub-blocking walls included in each blocking wall is thepositioning groove as mentioned above, that is, the positioning grooveis formed due to the existence of the blocking wall, and the positioninggroove is not obtained by grooving the second middle frame.

In the embodiment of the present disclosure, in the same blocking wallon the rim extending in the first direction, the interval between twosub-blocking walls forms a concave portion, which is the firstpositioning groove configured to place the first protruding portion orthe second positioning groove configured to place the second protrudingportion; in the same blocking wall on the rim extending in the seconddirection, the interval between two sub-blocking walls forms a concaveportion, which is the third positioning groove configured to place thethird protruding portion or the fourth positioning groove configured toplace the fourth protruding portion. Therefore, the blocking wallsarranged around the second middle frame correspond to the connectinglines between two adjacent positioning portions of the first sub-opticalfilm, and a certain interval should be set between the connecting lineextending in the first direction and the corresponding blocking wall toprovide deformation space for the first sub-optical film to expand orcontract in the second direction. In the same way, a certain intervalshould be set between the connecting portion extending in the seconddirection and the corresponding blocking wall to provide deformationspace for the first sub-optical film to expand or contract in the firstdirection, thus preventing the first sub-optical film from wrinkling dueto the obstruction of the blocking wall on the second middle frame whenit is deformed due to the change of ambient temperature.

For example, as shown in FIG. 4F to FIG. 4L, a boss 3221 is provided inthe second positioning groove 3220 between two sub-blocking walls 3231in the E2 region to the E4 region. The length of the boss 3221 in theextending direction of the first sub-edge portion 0101 of the firstsub-optical film 3101 may be 9.49 mm, the width of the boss 3221 may be0.72 mm, and the height of the boss 3221 perpendicular to the secondsupporting surface may be 2 mm. For example, the boss 3221 located inthe second positioning grooves 3220 may be located approximately in themiddle of the second positioning grooves 3220, so as to facilitate thedesign of the interval between the second protruding portion 0121 andthe boss 3221. In the embodiment of the present disclosure, the sizes ofthe boss 3221 in respective second positioning grooves 3220 are thesame, and the groove lengths of respective second positioning grooves3220 in the extending direction of the first sub-edge portion 0101 arethe same, so the size of the reserved interval between the secondprotruding portions 0121 and the boss 3221 can be changed by changingthe size of the parts of the second protruding portions 0121 located onboth sides of the opening 12 in the extending direction of the firstsub-edge portion 0101. For example, the length of the first positioninggroove 32100 between two sub-blocking walls 3231 in the E1 region in theextending direction of the first sub-edge portion 0101 may be 25.2 mm,and its depth may be 1.1 mm.

For example, as shown in FIG. 4F to FIG. 4L, the positioning groovebetween two sub-blocking walls 3231 in the E5 region and the E6 regionin the extending direction of the second sub-edge portion 0102 of thefirst sub-optical film 3101 may have a length of 26.2 mm, and a depth of1.1 mm. For example, the length of the first positioning groove 32100between two sub-blocking walls 3231 in the E5 region is the same as thatof the second positioning groove 3220 in the E6 region, the sizes of thepositioning portions located in different positioning grooves in theextending direction of the second sub-edge portion can be adjusted sothat the sizes of the intervals between different positioning groovesand corresponding positioning portions are different, thus realizing thecombination of accurate positioning and rough positioning.

For example, as shown in FIG. 4F and FIG. 4H, taking the verticalplacement of the first sub-optical film as an example, the directionindicated by the arrow in the Z direction is upward with the ground as areference. At this time, the first sub-edge portion is horizontallydisposed and the second sub-edge portion is vertically disposed. Forexample, there is an interval D between the connecting line 0130 on thefirst sub-edge portion 0101 on the upper side of the first sub-opticalfilm 3101 and opposite sides of the corresponding sub-blocking wall3231, which is a contraction space reserved for the first sub-opticalfilm 3101 to contract in the second direction. For example, the value ofthe interval D may be approximately 1.5 mm.

For example, as shown in FIG. 4F and FIG. 4L, there is an interval Jbetween the connecting line 0130 on the first sub-edge portion 0101 onthe lower side of the first sub-optical film 3101 and opposite sides ofthe corresponding sub-blocking wall 3231, and the interval J is anexpansion space reserved for the first sub-optical film 3101 to expandin the second direction. For example, the value of the interval J may beapproximately 2 mm.

For example, as shown in FIG. 4F, FIG. 4I and FIG. 4K, there is aninterval F between the connecting line 0130 located on one secondsub-edge portion 0102 of the first sub-optical film 3101 and oppositesides of the corresponding sub-blocking wall 3231, which is an expansionspace reserved for the first sub-optical film 3101 to expand in thefirst direction. For example, the value of the interval F may be in arange of 2.4˜2.9 mm. Similarly, there is an interval H between theconnecting line 0130 located on the other second sub-edge portion 0102of the first sub-optical film 3101 and opposite sides of thecorresponding sub-blocking wall 3231, which is an expansion spacereserved for the first sub-optical film 3101 to expand in the firstdirection. For example, the value of the interval H may be in a range of2.4˜2.9 mm.

FIG. 4M is a schematic diagram of a partial cross-sectional structure ofa backlight assembly provided by an embodiment of the presentdisclosure, FIG. 4N is a schematic diagram of a planar structure of asecond sub-optical film provided by an embodiment of the presentdisclosure, and FIG. 4O is a schematic diagram of a planar structure inwhich a second sub-optical film is matched with a second middle frameprovided by an embodiment of the present disclosure. As shown in FIG. 4Mto FIG. 4O, the backlight assembly further includes a second sub-opticalfilm 0300 including a plurality of second edge portions. The secondsub-optical film 0300 is located between the first sub-optical film 3101and the second supporting surface 3215 of the second middle frame 320,and the second supporting surface 3215 is configured to support thesecond sub-optical film 0300 and the first sub-optical film 3101.

For example, the second sub-optical film 0300 may be a diffuser plate.For example, the thickness of the second sub-optical film 0300 isgreater than that of the first sub-optical film 3101. For example, thesecond sub-optical film 0300 can be made of transparent materials suchas polymethyl methacrylate (PMMA) or polycarbonate (PC), and itsthickness is thicker (for example, in a range of 0.125˜0.4 mm), and itslight transmittance can be greater than 90%.

For example, as shown in FIG. 4C to FIG. 4O, the periphery of the secondsub-optical film 0300 includes a plurality of concave portions 0310,which are arranged in one-to-one correspondence with the plurality ofblocking walls 3230, and each concave portion 0310 is configured to beengaged with a corresponding blocking wall 3230 to fix the secondsub-optical film 0300. For example, each blocking wall 3230 is an inwardprotruding portion located in the rim of the second supporting portion321, and each concave portion 0310 is an inward concave portion locatedat the edge of the second sub-optical film 0300.

In the embodiment of the present disclosure, the blocking wall 3230protruding inward from the second supporting portion 321 is embeddedinto the concave portion 0310 of the second sub-optical film 0300 to fixthe position of the second sub-optical film 0300. In the embodiment ofthe present disclosure, the outline edge of the second sub-optical film(i.e., the second edge portion) is set into an irregular shape, that is,the outline edge of the second sub-optical film is no longer a straightline, but a broken line matched with the second middle frame, so thatthe second sub-optical film and the second middle frame can be directlyfixed without double-sided adhesive tape. Therefore, a certain movablespace can be reserved for the second sub-optical film, and the displayis prevented from being affected by deformation such as wrinkles causedby the restriction of the second middle frame when the secondsub-optical film expands or contracts.

For example, as shown in FIG. 4C to FIG. 4O, the second sub-optical film0300 includes a plurality of outline edges (i.e., a plurality of secondedge portions) corresponding to the plurality of rims 3202 of the secondsupporting portion 321 one by one. The embodiment of the presentdisclosure takes an example that the second sub-optical film 0300includes four outline edges, and the four outline edges enclose to formthe second sub-optical film with a substantially rectangular shape, butis not limited thereto. As long as a plurality of rims of the secondmiddle frame correspond to a plurality of outline edges of the secondsub-optical film one by one.

For example, as shown in FIG. 4C to FIG. 4O, the plurality of outlineedges of the second sub-optical film 0300 include a third sub-edgeportion 0301 extending in the first direction and a fourth sub-edgeportion 0302 extending in the second direction. For example, the lengthof the third sub-edge portion 0301 is greater than that of the fourthsub-edge portion 0302. In the embodiment of the present disclosure,taking the shape of the second sub-optical film being a rectangular asan example, the third sub-edge portion is a long side and the fourthsub-edge portion is a short side.

For example, as shown in FIG. 4N to FIG. 4O, the third sub-edge portion0301 includes a plurality of concave portions 0310 and a convexstructure 0320 located between adjacent concave portions. Therefore, theplurality of concave portions 0310 and the plurality of convexstructures 0320 are connected end to end to form a zigzag outline edge.In the same way, the fourth sub-edge portion 0302 is also a zigzagoutline edge formed by connecting the plurality of concave portions 0310and the plurality of convex structures 0320 end to end.

For example, as shown in FIG. 4N to FIG. 4O, the plurality of concaveportions 0310 include a first sub-concave portion 0311 and a pluralityof second sub-concaves 0312 located on the third sub-edge portion 0301.The blocking wall 3230 located in the first sub-concave portion 0311 isthe first blocking wall and the blocking wall 3230 located in the secondsub-concave portion 0312 is the second blocking wall.

For example, as shown in FIG. 4N to FIG. 4O, the blocking wall 3230located on the rim 3202 extending in the first direction includes twoouter sides opposite to each other in the first direction, and theconcave portion 0310 located on the third sub-edge portion 0301 includestwo inner sides opposite to each other in the first direction, and thetwo outer sides of the blocking wall 3230 corresponding to one concaveportion 0310 are located between the two inner sides of the concaveportion 0310.

For example, as shown in FIG. 4N to FIG. 4O, in the normal temperatureenvironment, there is an interval between two sides of the secondsub-concave portion and two sides of the corresponding blocking wall3230 which are close to the two sides of the second sub-concave portionin the first direction. For example, there may or may not be at leastone interval between each first sub-concave and the correspondingblocking wall in the first direction. For example, there are twointervals between each concave portion and the blocking wall located init, that is, there is no contact. One of the two intervals provides anexpansion space for the second sub-optical film, and the other providesa contraction space for the second sub-optical film. Thus, when thebacklight assembly provided by the embodiment of the present disclosureis in a high temperature environment (e.g., 50˜100° C.) or a lowtemperature environment (e.g., 0˜40° C.), there is enough expansion orcontraction space between the concave portion of the second sub-opticalfilm and the blocking wall of the second middle frame, so that thesecond sub-optical film can be prevented from being deformed due to theobstruction of the second middle frame during expansion or contraction.

For example, in order to facilitate fabrication, the width of theinterval for providing expansion space for the second sub-optical filmmay be equal to the width of the interval for providing contractionspace for the second sub-optical film.

For example, FIG. 4P is a partial enlarged view of E9 region in thebacklight assembly shown in FIG. 4O, and FIG. 4Q is a partial enlargedview of E10 region in the backlight assembly shown in FIG. 4O. As shownin FIG. 4N to FIG. 4Q, the first sub-concave portion 0311 located on thethird sub-edge portion 0301 includes two inner sides opposite to eachother in the first direction, and the first blocking wall is locatedbetween the two inner sides, and there are an interval K1 and aninterval K2 between the first blocking wall and the two inner sides,respectively. A sum of the sizes of intervals in the first directionbetween the first sub-concave portion 0311 and the sides of thecorresponding blocking wall (i.e., the first blocking wall) close to thefirst sub-concave portion (i.e., the sum of sizes of the interval K1 andthe interval K2) is a fourth space S4, that is, the difference betweenthe sizes of the first sub-concave portion 0311 and the correspondingblocking wall in the first direction is the fourth space S4.

Each second sub-concave portion 0312 located on the third sub-edgeportion 0301 includes two inner sides opposite to each other in thesecond direction, and each second blocking wall is located in the twoinner sides, there are an interval L1 and an interval L2 between thesecond blocking wall and the two inner sides, respectively. The sum ofsizes of intervals in the first direction between the second sub-concaveportion 0312 and the sides of the corresponding blocking wall (i.e., thesecond blocking wall) close to the second sub-concave portion (i.e., thesum of sizes of the interval L1 and the interval L2) is a fifth spaceS5. That is, the difference between the sizes of the second sub-concaveportion 0312 and the corresponding blocking wall in the first directionis the fifth space S5. The fourth space S4 is smaller than the fifthspace S5. Therefore, the first sub-concave portion is a concave portionfor accurate positioning, and the second sub-concave portion is aconcave portion for rough positioning. When the third sub-edge portionis an arc-shaped edge portion, the fourth space and the fifth space aresizes in the extending direction of the arc-shaped edge portion.

In the embodiment of the present disclosure, the combination of accuratepositioning and rough positioning is adopted between the secondsub-optical film and the second middle frame, which can not only ensurethe fixation of the second sub-optical film and the second middle frame,but also ensure that the second sub-optical film is not prone to wrinklein high temperature and high humidity environment, and does not affectnormal display.

For example, as shown in FIG. 4N to FIG. 4Q, the first sub-concaveportion 0311 is located approximately at the midpoint of the thirdsub-edge portion 0301, and a plurality of second sub-concaves 0312 arelocated on both sides of the first sub-concave portion 0311. In theembodiment of the disclosure, the first concave portion as the accuratepositioning concave portion is roughly arranged at the middle point ofthe third sub-edge portion of the second sub-optical film, and aplurality of rough positioning concave portions are distributed on bothsides of the accurate positioning concave portion, so that the secondsub-optical film can expand to the left and right (taking the Xdirection as the right as an example) with the accurate positioningconcave portion as the center in high temperature environment; or theparts of the second sub-optical film located at both sides of theaccurate positioning concave portion contract towards the middle underthe low temperature environment. Therefore, wrinkling of the long sideof the second sub-optical film during expansion or contraction can beavoided as much as possible.

For example, as shown in FIG. 4N to FIG. 4Q, the number of secondsub-concaves 0312 located on both sides of the first sub-concave portion0311 in the first direction is equal, and the plurality of secondsub-concaves 0312 located on both sides of the first sub-concave portion0311 are symmetrically distributed with the first sub-concave portion0311 as the center. Therefore, it is possible to ensure that the thirdsub-edge portion of the second sub-optical film expands or contractssymmetrically at high temperature or low temperature, so as tofacilitate the setting of the relative positional relationship betweenthe second sub-optical film and the second middle frame.

For example, as shown in FIG. 4N to FIG. 4Q, in the direction from themidpoint of the third sub-edge portion 0301 to the end points at bothsides, the fifth spaces S5 corresponding to the second sub-concaves 0312gradually increase to ensure that the second sub-optical film expandsfrom the center to both sides in the high temperature and high humidityenvironment. The closer to the edges of the second sub-optical film, thegreater the expansion of the second sub-optical film in the directionfrom the midpoint of the third sub-edge to the end points at both sides.Therefore, the closer to the edges of the second sub-optical film, thesize of the reserved interval between the second sub-concave portion andthe corresponding blocking wall presents an increasing trend, so as toensure that each position of the second sub-optical film will not havedeformation such as wrinkles which affects the display when expanding orcontracting due to temperature change in the vehicle-mountedenvironment.

For example, as shown in FIG. 4F to FIG. 4Q, the embodiment of thepresent disclosure takes the rim of the second supporting portion 321extending in the first direction arranged with seven blocking walls 3230as an example, and the above seven blocking walls 3230 are centered onthe fourth blocking wall 3230 (the blocking wall 3230 in the E1 region),and three blocking walls respectively on the left side and right sideare symmetrically distributed relative to the fourth blocking wall. Theembodiment of the present disclosure does not limit the number ofblocking walls, and the number of blocking walls can be adjustedaccording to the length and radian of the second middle frame. Forexample, in the direction perpendicular to the second supportingsurface, the height of the blocking wall 3230 may be 3.29 mm.

For example, as shown in FIG. 4F to FIG. 4Q, in an example of theembodiment of the present disclosure, the backlight assembly is a curvedsurface backlight assembly, and the length of the blocking wall 3230 inthe E4 region in the extending direction of the third sub-edge portion0301 may be 68.22 mm, and the length of the blocking wall 3230 in the E3region in the extending direction of the third sub-edge portion 0301 maybe 69.33 mm, the length of the blocking wall 3230 in the E2 region inthe extending direction of the third sub-edge portion 0301 may be 70.04mm, and the length of the blocking wall 3230 in the E1 region in theextending direction of the third sub-edge portion 0301 may be 69.21 mmIn the embodiment of the disclosure, the design of different lengths ofblocking walls at different positions can ensure that the second middleframe can better keep the uniformity of curved surface radian andimprove the yield of molding process, and can also reserve enoughcontraction space and expansion space for different positions of thesecond sub-optical film.

For example, as shown in FIG. 4F to FIG. 4Q, in the embodiment of thepresent disclosure, the third sub-edge portion of the second sub-opticalfilm 0300 is provided with seven concave portions corresponding to theseven blocking walls 3230 one by one as an example, and the length ofthe second sub-concave portion 0312 in the E4 region in the extendingdirection of the third sub-edge portion 0301 may be 71.32 mm, and sizesof the two intervals between the second sub-concave portion 0312 and theblocking walls 3230 located in it can both be 1.55 mm; the length of thesecond sub-concave portion 0312 in the E3 region in the extendingdirection of the third sub-edge portion 0301 may be 71.72 mm, and sizesof the two intervals between the second sub-concave portion 0312 and theblocking wall 3230 located in it may both be 1.19 mm; the length of thesecond sub-concave portion 0312 in the E2 region in the extendingdirection of the third sub-edge portion 0301 may be 71.92 mm, and sizesof the two intervals between the second sub-concave portion 0312 and theblocking wall 3230 located in it may both be 0.96 mm; the length of thefirst sub-concave portion 0311 in the E1 region in the extendingdirection of the third sub-edge portion 0301 may be 70.79 mm, and sizesof the two intervals between the first sub-concave portion 0311 and theblocking wall 3230 located in it may both be 0.79 mm.

The first sub-concave portion 0311 in the E1 region is taken as theaccurate positioning concave portion of the second sub-optical film0300, and the rough positioning concave portions on both sides aresymmetrically distributed relative to the accurate positioning concaveportion, and the reserved sizes of the intervals from the middle to bothsides is from small to large, so as to ensure that the secondsub-optical film expands from the center to both sides in hightemperature and high humidity environment. From the middle point to theboth end points of the third sub-edge portion, the closer it is to theedges of the second sub-optical film, the greater the expansion size ofthe second sub-optical film, and the closer it is to the edges of thesecond sub-optical film, the reserved sizes of the intervals between thesecond sub-concave portions and the corresponding blocking walls show anincreasing trend, which can ensure that respective positions of thesecond sub-optical film will not have deformation such as wrinkles whenexpanding or contracting due to temperature change in thevehicle-mounted environment.

For example, the depth by each concave portion 0310 on the thirdsub-edge portion 0301 concaved towards the center of the secondsub-optical film 0300 may be 3 mm.

For example, FIG. 4R is a partial enlarged view of E11 region of thebacklight assembly shown in FIG. 4O, and FIG. 4S is a partial enlargedview of E12 region of the backlight assembly shown in FIG. 4O. As shownin FIG. 4N to FIG. 4S, the plurality of concave portions 0310 include athird sub-concave portion 0313 and at least one fourth sub-concaveportion 0314 located on the fourth sub-edge portion 0302, and the atleast one fourth sub-concave portion 0314 is located at one side of thethird sub-concave portion 0313 in the second direction. For example, theembodiment of the present disclosure schematically shows that one thirdsub-concave portion and one fourth sub-concave portion are arranged onthe fourth sub-edge portion. At this time, the third sub-concave portionand the fourth sub-concave portion can be distributed approximatelysymmetrically with respect to the midpoint of the fourth sub-edgeportion. The present disclosure is not limited thereto, one fourthsub-edge can be provided with a plurality of fourth sub-concaveportions, which are all located on the same side of the thirdsub-concave portion, and the third sub-concave portion and the pluralityof fourth sub-concave portions are roughly evenly distributed on thefourth sub-edge portion.

For example, as shown in FIG. 4N to FIG. 4S, in the normal temperatureenvironment, there are intervals between the two sides of the blockingwall located in each concave portion on the fourth sub-edge portion 0302and the corresponding two sides of the concave portion in the seconddirection. That is, there are two intervals arranged along the seconddirection between the concave portion on the fourth sub-edge portion andthe corresponding blocking wall.

For example, as shown in FIG. 4N to FIG. 4S, taking one rim extending inthe second direction among the plurality of rims 3202 as an example, theblocking wall 3230 on the rim includes two opposite sides in the seconddirection, and the blocking wall 3230 is located in the thirdsub-concave portion 0313 on the fourth sub-edge portion 0302, and thereare two intervals between the third sub-concave portion 0313 and theblocking wall, namely, an interval M1 and an interval M2. There are twointervals between the fourth sub-concave portion 0314 located on thefourth sub-edge portion 0302 and the blocking wall located therein,namely, an interval N1 and an interval N2.

In the normal temperature environment, one of the two intervals arrangedbetween each concave portion and the corresponding blocking wall in thesecond direction provides an expansion space for the second sub-opticalfilm, and the other provides a contraction space for the secondsub-optical film. Therefore, upon the backlight assembly provided by theembodiment of the present disclosure being in a high-temperatureenvironment or a low-temperature environment, there is enough expansionspace or contraction space between the second sub-optical film and theblocking wall of the second middle frame, so that it is possible toprevent the second sub-optical film from being hindered by the secondmiddle frame during expansion or contraction, resulting in wrinkles andother deformation affecting display.

For example, in order to facilitate fabrication, among the above twointervals between each concave portion and the corresponding blockingwall, the width of the interval providing expansion space for the secondsub-optical film may be equal to the width of the interval providingcontraction space for the second sub-optical film.

For example, in the normal temperature environment, the sum of the sizesof the intervals in the second direction between sides of the thirdsub-concave portion 0313 and sides of the corresponding blocking walls3230 close to the sides of the third sub-concave portion 0313 is smallerthan the sum of the sizes of the intervals in the second directionbetween sides of the fourth sub-concave portion 0314 and sides of thecorresponding blocking walls 3230 close to the sides of the fourthsub-concave portion 0314. For example, the sum of the sizes of theinterval M1 and the interval M2 between the third sub-concave portion0313 and the corresponding blocking wall 3230 in the second direction issmaller than the sum of the sizes of the interval N1 and the interval N2between the fourth sub-concave portion 0314 and the correspondingblocking wall 3230 in the second direction, so that the thirdsub-concave portion 0313 is an accurate positioning concave portion andthe fourth sub-concave portion 0314 is a rough positioning concaveportion. In the embodiment of the present disclosure, the combination ofaccurate positioning and coarse positioning is adopted between thefourth sub-edge portion of the second sub-optical film extending in thesecond direction and the rim of the second middle frame extending in thesecond direction, which can not only ensure the fixation between thesecond sub-optical film and the second middle frame, but also ensurethat the second sub-optical film in the high-temperature andhigh-humidity environment is not easily deformed in the seconddirection.

In the embodiment of the disclosure, under the condition that the sizeof the fourth sub-edge portion is small, the fourth sub-edge portion canbe provided with one accurate positioning concave portion and at leastone rough positioning concave portion, so that the diffuser sheet canexpand to one side with the accurate positioning concave portion as thecenter in a high temperature environment; or a part of the diffusersheet at one side of the accurate positioning concave portion contractsto the accurate positioning concave portion when the diffuser sheet isin a low temperature environment. Of course, the embodiments of thepresent disclosure are not limited thereto. Upon the length of thefourth sub-edge portion being long and the number of rough positioningconcave portions is large, the rough positioning concave portions canalso be distributed on both sides of the accurate positioning concaveportion to minimize the size change of the second sub-edge portion ofthe second sub-optical film when expanding or contracting.

For example, an example of the embodiment of the present disclosure isdescribed by taking two blocking walls 3230 arranged on the rimextending in the second direction of the second supporting portion 321as an example. For example, in the direction perpendicular to the secondsupporting surface, the height of the blocking wall 3230 may be 3.29 mm.

For example, as shown in FIG. 4N to FIG. 4S, in an example of theembodiment of the present disclosure, the backlight assembly is a curvedsurface backlight assembly, and the length of the blocking wall 3230 inthe E11 region in the extending direction of the fourth sub-edge portion0302 may be 74.76 mm, and the length of the blocking wall 3230 in theE12 region in the extending direction of the fourth sub-edge portion0302 may be 77.46 mm Taking the vertical placement of the secondsub-optical film provided by the embodiment of the present disclosure asan example, the blocking wall in the E11 region is located at the upperside and the blocking wall in the E12 region is located at the lowerside, and the length of the blocking wall in the E12 region is longerthan that in the E11 region, which can ensure that the second middleframe provides a better load-supporting function for the secondsub-optical film, so as to ensure that the second sub-optical film canmaintain stability when the backlight assembly is applied tohigh-intensity vibration conditions.

For example, as shown in FIG. 4N to FIG. 4S, a case that the fourthsub-edge portion of the second sub-optical film 0300 is provided withtwo concave portions corresponding to two blocking walls 3230 one by oneis taken as an example, the length of the third sub-concave portion 0313in the E11 region in the extending direction of the fourth sub-edgeportion 0302 may be 76 mm, and the sizes of the two intervals betweenthe third sub-concave portion 0313 and the blocking wall 3230 located init may be 0.62 mm; the length of the fourth sub-concave portion 0314 inthe E12 region in the extending direction of the fourth sub-edge portion0302 may be 79.2 mm, and the sizes of the two intervals between thefourth sub-concave 0314 and the blocking wall 3230 located in it mayboth be 0.87 mm. The third sub-concave portion 0313 in the E11 region isused as the accurate positioning concave portion of the secondsub-optical film 0300, and a rough positioning concave portion isarranged on one side of the accurate positioning concave portion toensure that the second sub-optical film has enough expansion andcontraction space in the extending direction of the fourth sub-edgeportion in the high temperature and high humidity environment, and thesecond sub-optical film is not easy to have wrinkles and otherdeformation affecting the display.

For example, the depth of each concave portion 0310 located on thefourth sub-edge portion 0302 to the center of the second sub-opticalfilm 0300 may be 3.2 mm.

For example, as shown in FIG. 4N to FIG. 4S, a fifth positioning groove3240 is included between two adjacent blocking walls 3230 in theplurality of blocking walls 3230, and a convex structure 0320 isincluded between two adjacent concave portions 0310 in the plurality ofconcave portions 0310, and the convex structure 0320 is located in thefifth positioning groove 3240.

For example, as shown in FIG. 4N to FIG. 4S, the lengths of the concaveportions 0310 located on the third sub-edge portion 0301 of the secondsub-optical film 0300 in the first direction are all smaller than thesizes of the convex structures 0320 located on the third sub-edgeportion 0301 in the first direction. For example, the lengths of theconcave portions 0310 located on the fourth sub-edge portion 0302 of thesecond sub-optical film 0300 in the second direction are all greaterthan the size of the convex structure 0320 located on the fourthsub-edge portion 0302 in the second direction.

For example, as shown in FIG. 4N to FIG. 4S, the length of the fifthpositioning groove 3240 formed between two adjacent blocking walls 3230arranged on the rim extending in the second direction of the secondmiddle frame 320 may be 25.58 mm in the second direction.

For example, in order to further ensure the stability of the secondsub-optical film, an adhesive may be provided between the secondsub-optical film and the second supporting surface to bond the secondsub-optical film to the second middle frame. For example, the adhesivematerial can be located in the middle of the third sub-edge portion ofthe second sub-optical film to reduce the influence of the position ofthe adhesive material on the deformation trend of the second sub-opticalfilm when expanding or contracting.

For example, FIG. 4T is a partial cross-sectional view of a backlightassembly including a back plate provided by an embodiment of the presentdisclosure. Except for the matching relationship with the firstsub-optical film and the second sub-optical film, the back plate in theembodiment of the present disclosure may have the same characteristicsas the back plate shown in FIG. 1A. For example, as shown in FIG. 4T, atleast part of the back plate 400 of the backlight assembly is located onthe side of the second middle frame 320 away from the first sub-opticalfilm 3101.

For example, the side plate 420 of the back plate 400 extends from theouter edge of the second supporting portion 413 toward the firstsub-optical film 3101. For example, the side plate 420 may have anannular structure that surrounds the first sub-optical film 3101.

For example, the first supporting portion 413 is used to support thefirst sub-optical film 3101 and the second sub-optical film 0300.

For example, FIG. 4U and FIG. 4V are two side views of the back plate,FIG. 4W is a schematic diagram of the positional relationship among afirst sub-optical film, a second middle frame and a back plate, and FIG.4X is a schematic diagram of the positional relationship among a secondsub-optical film, a second middle frame and a back plate. FIG. 4U is aside view of the back plate located at the outer side of the secondsub-edge portion of the first sub-optical film, and FIG. 4V is a sideview of the back plate located at the outer side of the first sub-edgeportion of the first sub-optical film. As shown in FIG. 4U to FIG. 4X,the side plate 420 is located at the outer side of the second supportingportion 321 and surrounds the second middle frame 320. The side plate420 includes a first side plate rim extending in the first direction anda second side plate rim extending in the second direction. The firstside plate rim is located at the outer side of the rim extending in thefirst direction of the second middle frame 320, and the second sideplate rim is located at the outer side of the rim extending in thesecond direction, so the length of the first side plate rim is greaterthan that of the second side plate rim. In the embodiment of the presentdisclosure, taking the side plates including two first side plate rimsand two second side plate rims as an example, the four side plate rimssurround to form the side plates of the back plate, and the side platesof the back plate enclose the second supporting portion.

For example, as shown in FIG. 4U to FIG. 4X, a plurality of firstavoiding grooves 0421 provided on the side plate 420 include a partlocated on the first side plate rim and another part located on thesecond side plate rim.

For example, as shown in FIG. 4U to FIG. 4X, the plurality of firstavoiding grooves 0421 on the first side plate rim extending in the firstdirection are opposite to the second positioning grooves 3220, and apart of the orthographic projection of the second positioning portion0120 on the plane where the second supporting surface is located is inthe corresponding second positioning groove 3220 and first avoidinggroove 0421. That is, the second positioning portion 0120 passes throughthe corresponding second positioning groove 3220 and then extends intothe first avoiding groove 0421. For example, in the normal temperatureenvironment, a part of the first avoiding groove 0421 close to the outeredge is not covered by the second positioning portion 0120, and acertain gap is reserved for the expansion space when the firstsub-optical film expands.

For example, as shown in FIG. 4U to FIG. 4X, in an example of theembodiment of the present disclosure, the first sub-edge portion 0101 ofthe first sub-optical film 3101 is provided with one first positioningportion 0110 (i.e., the first protruding portion 0111) located in thecenter and three second positioning portions 0120 (i.e., secondprotruding portions 0121 including openings 12) located on both sides ofthe first positioning portion 0110. The rim of the second middle frame320 extending in the first direction is provided with one firstpositioning groove 32100 for placing one first positioning portion 0110and six second positioning grooves 3220 for placing six secondpositioning portions 0120, respectively. The first side plate rim of theside plate 420 of the back plate 400 extending in the first directioncan be provided with six first avoiding grooves 0421 corresponding tothe six second positioning grooves 3220 one by one, for the avoidance ofthe second protruding portion 0121 of the first sub-optical film 3101.That is, the second protruding portion 0121 protrudes away from thecenter of the first sub-optical film 3101, passes through the secondpositioning groove of the rim of the second middle frame 320, andextends into the notch (i.e., the first avoiding groove 0421) providedby the side plate 420.

For example, the first protruding portion 0111 of the first sub-opticalfilm 3101 protrudes away from the center of the first sub-optical film3101, but does not exceed the first positioning groove 32100 of thesecond middle frame 320. The size of the first protruding portion 0111in the second direction is smaller than that of the second protrudingportion 0121 including the opening (this size includes the size of theopening), therefore, the side plate 420 is not provided with an avoidinggroove at the position directly opposite to the first protruding portion0111.

For example, the width of the first avoiding groove 0421 provided on thefirst side plate rim extending in the first direction may be 28 mm, andthe depth of the first avoiding groove 0421 in the directionperpendicular to the second supporting surface 3215 may be 2.3 mm. Forexample, among the six first avoiding grooves 0421 arranged on the firstside plate rim extending in the first direction, the positions of thethree first avoiding grooves 0421 located on one side of the firstprotruding portion 0111 are respectively 1/15 of the length of the firstside plate rim, ¼ of the length of the first side plate rim and ⅓ of thelength of the first side plate rim.

For example, as shown in FIG. 4U to FIG. 4X, the first avoiding groove0421 on the second side plate rim extending in the second direction isopposite to the third positioning groove 2100 or the fourth positioninggroove 2200, and a part of the orthographic projection of the thirdpositioning portion 1100 on the plane where the second supportingsurface 3215 is located is in the third positioning groove 2100 and thecorresponding first avoiding groove 0421, and a part of the orthographicprojection of the fourth positioning portion 1200 on the plane where thesecond supporting surface 3215 is located is in the fourth positioninggroove 2200 and the corresponding first avoiding groove 0421. That is,the third positioning portion 1100 extends into the corresponding firstavoiding groove 0421 after passing through the third positioning groove2100, and the fourth positioning portion 1200 extends into thecorresponding first avoiding groove 0421 after passing through thefourth positioning groove 2200.

For example, in the normal temperature environment, the part of thefirst avoiding groove 0421 close to the outer edge is not covered by thesecond positioning portion 0120, the third positioning portion 1100 orthe fourth positioning portion 1200, and a certain gap is reserved forthe expansion space when the first sub-optical film expands.

For example, as shown in FIG. 4U to FIG. 4X, in an example of theembodiment of the present disclosure, one third positioning portion 1100(i.e., the third protruding portion 0112) and one fourth positioningportion 1200 (i.e., the fourth protruding portion 0122) located at oneside of the third positioning portion 1100 are provided at the secondsub-edge portion 0102 of the first sub-optical film 3101, and a rimextending in the second direction of the second middle frame 320 isprovided with one third positioning groove 2100 for placing the thirdpositioning portion 1100 and one fourth positioning groove for placingthe fourth positioning portion 1200. The second side plate rim of theside plate 420 of the back plate 400 extending in the second directionis provided with two first avoiding grooves 0421 corresponding to thetwo positioning grooves one by one, for avoiding the third protrudingportion 0112 and the fourth protruding portion 0122 of the firstsub-optical film 3101. That is, the third protruding portion 0112 andthe fourth protruding portion 0122 protrude away from the center of thefirst sub-optical film 3101, pass through the positioning groove of therim of the second middle frame 320, and extend into the notch (i.e., thefirst avoiding groove 0421) provided by the side plate 420.

For example, the width of the first avoiding groove 0421 provided on thesecond side plate rim extending in the second direction may be 26 mm,and the depth of the first avoiding groove 0421 in the directionperpendicular to the second supporting surface 3215 may be 2.1 mm. Forexample, the positions of the two first avoiding grooves 0421 providedon the second side plate rim extending in the second direction are ⅓ ofthe length of the second side plate rim and ⅔ of the length of thesecond side plate rim, respectively.

For example, as shown in FIG. 4U to FIG. 4X, the side plate 420 furtherincludes a plurality of second avoiding grooves 422, each of which islocated on the second side plate rim extending in the second directionand corresponds to the fifth positioning groove 3240 of the secondmiddle frame 320, and a part of the orthographic projection of theconvex structure 0320 on the plane where the second supporting surface3215 is located is in the corresponding fifth positioning groove 3240(i.e., the space between two blocking walls) and the second avoidinggroove. For example, in the normal temperature environment, in thedirection perpendicular to the second supporting surface, the edge ofthe second avoiding groove 422 close to the outer side is flush with theouter side edge of the convex structure 0320.

For example, as shown in FIG. 4U to FIG. 4X, in an example of theembodiment of the present disclosure, the edge of the second sub-opticalfilm 0300 extending in the second direction is provided with one convexstructure 0320, and the rim of the second middle frame 320 extending inthe second direction is provided with one fifth positioning groove 3240for placing the convex structure 0320. The second side plate rim of theside plate 420 of the back plate 400 extending in the second directionis provided with one second avoiding groove 422 corresponding to thefifth positioning groove 3240, which is used for avoiding the convexstructure 0320 of the second sub-optical film 0300. That is, the convexstructure 0320 protrudes away from the center of the second sub-opticalfilm 0300, passes through the fifth positioning groove of the rim of thesecond middle frame 320, and extends into the notch (i.e., the secondavoiding groove 422) provided on the side plate 420.

For example, the width of the second avoiding groove 422 disposed on thesecond side plate rim extending in the second direction may be 27 mm,and the depth of the second avoiding groove 422 in the directionperpendicular to the second supporting surface 3215 may be 4.8 mmBecause the second sub-optical film is located between the firstsub-optical film and the second middle frame, the depth of the secondavoiding groove for avoiding the convex structure of the secondsub-optical film is deeper than that of the first avoiding groove foravoiding the protruding portions of the first sub-optical film.

For example, as shown in FIG. 4U to FIG. 4X, the second side plate rimof the side plate 420 extending in the second direction includes twofirst avoiding grooves 0421 and one second avoiding groove 422, and thesecond avoiding groove 422 is located between the two first avoidinggrooves 0421. For example, the second avoiding groove 422 is located inthe middle of the second side plate rim, and the three avoiding grooveslocated on the second side plate rim are arranged at equal intervals.

The embodiment of the present disclosure is described by taking the backplate 400 as a structure in a backlight assembly as an example. But theembodiment is not limited thereto, for example, the back plate can alsobe a structure outside the backlight assembly and is the back plate ofthe display device. The second middle frame located in the backlightassembly in the embodiment of the present disclosure may be anothermiddle frame in the display device, so the display device provided bythe embodiment of the present disclosure includes two middle frames. Inthe present disclosure, two middle frames are disposed in the curvedsurface display device and only the second middle frame is fixed on thebottom plate of the back plate, the assembly tolerance can be minimized,and then the curvature accuracy of the display device can be improved.

For example, the curved surface display device provided by theembodiment of the present disclosure can be a vehicle-mounted curvedsurface display device applied to an automobile.

For example, FIG. 5A is a schematic plan view of a strip-shaped lampplate in a light source component shown in FIG. 1A and FIG. 1B, FIG. 5Bis a schematic plan view of an adapter plate connected with thestrip-shaped lamp plate, and FIG. 5C a schematic diagram of assembling aback plate and a light source component. As shown in FIGS. 3C and 5A-5C,the light source component 330 included in the backlight assemblyincludes a plurality of strip-shaped lamp plates 3310, and lightemitting diodes 331 are arranged on each strip-shaped lamp plate 3310 inan array. The reflective sheet 340 is located on a light emittingsurface of the light source component 330 and exposes the light emittingdiodes 331, that is, the reflective sheet is located on a side of thelight source component facing the display panel, and includes aplurality of openings for exposing a plurality of light emitting diodes,so that the light emitted by the light emitting diodes will not beblocked by the reflective sheet.

For example, as shown in FIG. 5A to FIG. 5C, the strip-shaped lamp plate3310 includes a positioning hole 3312, and a positioning protrusioncorresponding to the positioning hole 3312 is arranged on one side ofthe bottom wall of the back plate facing the light source component 330,and the positioning hole 3312 is matched with the positioning protrusion(for example, the positioning hole is sleeved on the positioningprotrusion) to realize the positioning of the strip-shaped lamp plate.One side of the strip-shaped lamp plate 3310 facing the bottom wall canbe provided with double-sided adhesive tape, and the strip-shaped lampplate 3310 is positioned through the positioning hole 3312 and fixedlyconnected with the bottom wall through the double-sided adhesive tape.

For example, as shown in FIG. 5A to FIG. 5C, the strip-shaped lamp plate3310 further includes a third fixing hole 3313, and the reflective sheet340 located on the side of the strip-shaped lamp plate 3310 away fromthe bottom wall can be fixedly connected with the bottom wall throughthe third fixing hole 3313, thereby further fixing the strip-shaped lampplate 3310.

For example, as shown in FIG. 3E and FIG. 5A, the reflective sheet 340includes a fourth fixing hole 341 corresponding to the third fixing hole3313, and the reflective sheet 340 and the strip-shaped lamp plate 3310can be fixed on the back plate by using nylon rivets penetrating throughthe fourth fixing hole and the third fixing hole.

For example, as shown in FIG. 5C, the extending direction of eachstrip-shaped lamp plate 3310 is parallel to the second edge 4112, thatis, the extending direction of the strip-shaped lamp plate 3310intersects with the extending direction of the first side 4111 with anarc shape, so that the curved surface bottom wall of the back plate canbe prevented from being deformed or damaged due to the stress differencewith the strip-shaped lamp plate. For example, the plurality of striplamps 3310 may be arranged in the extending direction of the first side4111, but not limited thereto, and the plurality of strip lamps may alsobe arranged in an array.

For example, as shown in FIG. 5A to FIG. 5C, each strip-shaped lampplate 3310 further includes an adapter plate connector 3311. Thebacklight assembly also includes at least one strip-shaped adapter plate350 located on the side of the bottom wall facing the display panel.Each adapter plate 350 includes a plurality of light bar connectors 351to connect the adapter plate connectors 3311 of a plurality ofstrip-shaped lamp plate 3310. That is, each adapter plate 350 isconnected with a plurality of strip-shaped lamp plates 3310.

For example, each adapter plate 350 extends in the extending directionof the first side 4111, and a plurality of adapter plates 350 arearranged in the extending direction of the first side 4111 and extendsalong the second edge 4112 of the bottom wall, and the adapter plates350 are all located at one side of the light source component 330.

For example, the material of the adapter plate has flexiblecharacteristics, and is arranged on the curved surface bottom wall 411to form an arc-shaped adapter plate with a certain curvature.

For example, the edge of the reflective sheet 340 extending in theextending direction of the first side of the bottom wall may be providedwith a slot, the edge provided with the slot corresponds to the adapterplate, and the slot is used to avoid the connection position between theadapter plate connector 3311 and the light bar connector 351.

For example, as shown in FIG. 5A to FIG. 5C, the adapter plate 350 isalso provided with an adapter plate fixing hole 353 to realize the fixedconnection with the bottom wall.

For example, the reflective sheet arranged on the bottom wall mayinclude two sub-reflective sheets which are arranged along the firstdirection, and each sub-reflective sheet is fixed on the curved surfacebottom wall by adhesive materials (such as double-sided adhesive) andfixing members (such as nylon rivets). For example, the reflectivesheets are spliced in sections, and the splice between twosub-reflective sheets is attached to the bottom wall with double-sidedadhesive tape. The above-mentioned sectional design can ensure that thereflective sheets are not prone to bump on the curved surface bottomwall. For example, push-in self-locking nylon rivets can be used to fixthe reflective sheet and light source components (such as light bars) onthe curved surface bottom wall of the back plate. For example, thefixing holes provided on the reflective sheet which are penetrated bynylon rivets are arrayed along the first direction and the seconddirection. For example, the interval between two adjacent fixing holesarranged in the first direction can be 72 mm, and the interval betweentwo adjacent fixing holes arranged in the second direction can be 96 mm.For example, the edge of the reflective sheet extending in the extendingdirection of the curved long side of the bottom wall may be providedwith a T-shaped groove, which is used to avoid the connection positionbetween the adapter plate connector (not shown) of the light sourcecomponent and the light bar connector (not shown), so as to avoidstructural interference between the reflective sheet and the connector.

For example, FIG. 5D is a plan view of a side of the back plate awayfrom the display panel. For example, as shown in FIG. 5A to FIG. 5D, theadapter plate 350 further includes a driving connector 352 to connectthe strip-shaped lamp plate 3310 to the light source driving plate 700located on the side of the back plate away from the display panel. Forexample, the driving connector 352 may be connected to the light sourcedriving plate 700 through a Flexible Flat Cable (FFC) 701.

For example, at least two strip-shaped lamp plates 3310 connected witheach adapter plate 350 can reduce the number of strip-shaped lamp plateoutput lines by connecting to the adapter plates 350, thereby reducingthe number of strip-shaped lamp plate output ports, that is, reducingthe number of driving connectors 352.

For example, one adapter plate 350 may be provided with eight light barconnectors 351 to be connected with the adapter plate connectors 3311 ofeight light bar plates 3310 to reduce the number of output ports of thelight bar plates to three. That is, the adapter plate 350 connected withthe eight strip-shaped lamp plates 3310 may be provided with threedriving connectors 352 as output ports of the eight strip-shaped lampplates 3310, thereby reducing the output ports of the strip-shaped lampplates. The embodiment of the present disclosure schematically showsthat the number of the output ports of eight strip-shaped lamp plates isreduced to three, but it is not limited thereto, and the number of theoutput ports can also be one, two, four, etc., as long as the number ofthe output ports of the strip-shaped lamp plates is less than the numberof the strip-shaped lamp plates. FIG. 5C schematically shows a casewhere two adapter plates are connected with sixteen strip-shaped lampplates, the number of the strip-shaped lamp plates connected with theadapter plates is not limited in the embodiment of the presentdisclosure, and can be set according to actual product requirements.

For example, FIG. 5E is a partial side view of the connecting portion ofthe back plate shown in FIG. 1A. As shown in FIG. 5D to FIG. 5E, astrip-shaped outlet hole 4120 is formed at the part of the connectingportion 412 connecting with one of the two first edges 4111 of thebottom wall 411, and a major axis of the strip-shaped outlet hole 4120is parallel to the first side 4111. For example, a flexible cable 701passes through the strip-shaped outlet hole 4120 to realize theconnection between the light source component 330 and the light sourcedriving plate 700. In the embodiment of the disclosure, the strip-shapedoutlet hole with the major axis parallel to the first side is arrangedat the connecting portion, so that the influence of the outlet hole onthe strength of the connecting portion can be reduced.

For example, the driving connector 352 of the adapter plate 350 can beconnected with a flexible flat cable 701, which passes through thestrip-shaped outlet hole 4120 provided on the connecting portion 412 andextends to the side of the bottom wall 411 away from the display panelto be connected with the light source driving plate 700 located on theback of the display device. In the embodiment of the present disclosure,the strip-shaped outlet hole is arranged at the connecting portion, sothat the lamp wire connecting the light source component and the lightsource driving plate passes through the connecting portion instead ofthe bottom wall, and the influence of the outlet hole on the strengthand curvature of the bottom wall can be reduced.

For example, the light source driving plate 700 can be connected with anexternal power supply to drive each light emitting diode by voltagesignals such as partitioning and/or time sharing.

For example, the light source driving plate 700 may be connected throughsignal lines such as power lines, clock lines, input/output lines (I/Olines) to control the operation timing of the light source driving plate700. For example, the display device can achieve the effects of goodcontrast and high brightness by controlling the light-emitting diodes indifferent areas.

Upon the brightness of the light source of the backlight assembly isrequired to be high, the number of light emitting diodes needs to be setup more. Assuming that each strip-shaped lamp plate is connected to thelight source driving plate on the side of the back plate away from thedisplay panel through a signal line, it is necessary to open a pluralityof connection vias in the bottom wall of the back plate, which willaffect the strength of the bottom wall. In the embodiment of thedisclosure, by arranging the adapter plates corresponding to theplurality of strip-shaped lamp plates, the number of output ports of thestrip-shaped lamp plates can be reduced, thereby reducing the number ofopenings on the back plate to ensure the strength of the back plate.

Based on the above embodiments, the present disclosure also providessuch a technical scheme that a display device includes a display panel;a backlight assembly located on a non-display side of the display paneland including a plurality of strip-shaped lamp plates, each of theplurality of strip-shaped lamp plates extends along a first direction; aback plate, at least part of the back plate being located at a side ofthe backlight assembly away from the display panel, wherein the backplate includes a bottom wall and a side wall connected with the edge ofthe bottom wall; the plurality of strip-shaped lamp wall are located ona side of the bottom wall facing the display panel, the backlightassembly further includes at least one adapter plate on the side of thebottom wall facing the display panel, the adapter plate extends along asecond direction intersecting with the first direction, and each adapterplate is connected with at least two strip-shape lamp plates to providedriving signals for them.

In some examples, each strip-shaped lamp plate includes an adapter plateconnector, and each adapter plate includes a plurality of light barconnectors to connect the adapter plate connectors of the plurality ofstrip-shaped lamp plates, respectively.

In some examples, the bottom wall includes a first bottom edge extendingalong the first direction and a second bottom edge extending along thesecond direction, and a part of the side wall connected with the secondbottom edge close to the adapter plate is provided with an outlet hole;the display device further includes a light source driving plate,located at a side of the bottom wall away from the display panel, andthe adapter plate being connected with the light source driving platethrough a wire led out from the outlet hole.

In some examples, the bottom wall is a curved structure, and the secondbottom edge is a curved edge.

In some examples, the outlet hole is a strip-shaped outlet hole, and amajor axis of the strip-shaped outlet hole is parallel to the secondbottom edge.

In some examples, the backlight assembly further includes an opticalfilm and a middle frame, the middle frame being located at a side of theoptical film away from the display panel and being configured to supportthe optical film.

It should be noted that the side wall provided with the outlet hole inthis technical scheme is the connecting portion 412 in the embodimentshown in FIG. 5E; the first bottom edge of the bottom wall in thistechnical scheme is the second edge 4112 in the embodiment shown in FIG.2A, and the second bottom edge is the first edge 4111 in the embodimentshown in FIG. 2A; the middle frame in this technical scheme is thesecond middle frame 320 in the embodiment shown in FIG. 1A. Othertechnical features not described in detail can refer to the aboveembodiments.

For example, FIG. 6A is a schematic partial cross-sectional view of theassembly of the first middle frame, the backlight assembly and the backplate. As shown in FIG. 6A, a side of the first middle frame 200 awayfrom the display panel 100 in the embodiment of the present disclosurepresses against the optical film 310, that is, the surface of the firstmiddle frame 200 away from the display panel 100 contacts the opticalfilm 310 to press and fix the optical film 310 to ensure the flatness ofthe optical film 310.

For example, FIG. 6B is a schematic plan view of the first middle frameshown in FIGS. 1A and 1B, FIG. 6C is a partially enlarged schematic viewat a position D in FIG. 6B, and FIG. 6D is a schematic side view of thefirst middle frame in FIG. 6C. As shown in FIG. 1B and FIG. 6A to FIG.6D, the first middle frame 200 may be a continuous ring structure thatsurrounds the display panel 100.

For example, as shown in FIGS. 6A and 6B, the first middle frame 200includes an outer rim 210 surrounding the display panel 100, and atleast part of the outer rim 210 is located at the outer side of the sideplate 420 of the back plate 400 and fixedly connected with the sideplate 420. For example, a part of the outer rim of the first middleframe can be connected with the side plate to realize the positioning ofthe first middle frame, and another part of the outer rim of the firstmiddle frame can be fixedly connected with the side plate to realize theposition fixing. For example, FIG. 6D shows a snap hole 2020 on theouter rim of the first middle frame, and a snap protrusion correspondingto the snap hole 2020 is also arranged on the side plate of the backplate to be matched with the snap hole to realize rough positioning ofthe first middle frame. That is, the snap hole of the outer rim issleeved on the snap protrusion on the side plate to realize the coarsepositioning of the first middle frame.

For example, in a direction perpendicular to the bottom wall, the firstmiddle frame may be supported by the side plate of the back plate. Theouter rim of the first middle frame includes a connecting hole 2021, andthe side plate of the back plate includes a screw hole opposite to theconnecting hole 2021 of the outer rim. Screws can be used to penetratethrough the connecting holes and screw holes, and the screws penetratethrough the connecting holes 2021 of the outer rim to engage with thescrew holes of the side plate, so that the first middle frame and theside plate of the back plate are fixedly connected, and the fixingdirection is perpendicular to the side plate. In the embodiment of thepresent disclosure, the connecting hole in the first middle frame (theconnecting hole 2021 shown in FIG. 6D) is only a via hole penetrated bya screw, rather than a threaded hole for engaging connection with ascrew, so even if the expansion and contraction displacement generatedby the first middle frame around the screw is large, the obstruction ofthe screw may cause large deformation of the connecting hole, and therewill be no failure of the connecting hole.

For example, the material of the first middle frame 200 may be a lightshielding material to shield an edge region of the display panel 100.For example, the material of the first middle frame 200 may be aflexible material to bend as other structures bend. For example, thematerial of the first middle frame 200 may be polycarbonate (PC).

For example, the hardness of the material of the second middle frame 320in the embodiment of the present disclosure is greater than that of thematerial of the first middle frame 200.

In the embodiment of the present disclosure, because the positions andsupported film layers of the first middle frame and the second middleframe are different, the hardness of the two materials is different. Thehardness of the material selected for the first middle frame is low, sothat the curvature of the first middle frame can be determined by thecurvature of the front frame on a side of the first middle frame awayfrom the display panel. Even when deformation such as expansion withheat and contraction with cold occurs, the front frame is pressed withthe first middle frame, so that the variation of curvature of the firstmiddle frame can be minimized In addition, the thickness of the firstmiddle frame provided by the embodiment of the present disclosure isthin, for example, the thickness of the first middle frame is 0.8 mm,which can improve its curved surface forming rate. The second middleframe is located on the bottom plate of the back plate, which plays arole in supporting the optical film by adopting a material with higherhardness, and can be stably arranged on the bottom plate to preventunnecessary deformation caused by soft material of the second middleframe, thereby ensuring the curvature accuracy of the optical film.

The first middle frame and the second middle frame which are separatedfrom each other in the display device provided by the embodiment of thedisclosure can ensure the curvature precision of each middle frame afterthe curved surface is formed; in addition, the first middle frame andthe second middle frame can be formed by using different materials, andare formed with different thicknesses to ensure a good fit with thecurvatures of other structures, so that the assembly tolerance can bereduced and the curvature accuracy of the display device can beimproved.

For example, as shown in FIG. 6A to FIG. 6D, the first middle frame 200includes a third supporting portion 230 configured to support thedisplay panel 100, and the third supporting portion 230 includes asecond arc strip portion 220 corresponding to the first arc stripportion 4131, and the second arc strip portion 220 has the same bendingdirection as the first arc strip portion 4131. According to theembodiment of the present disclosure, by setting the first middle framesupporting the display panel as a curved surface structure, the displaypanel can be guaranteed to have a predetermined curvature.

For example, the third supporting portion 230 includes two second arcstrip portions 220 opposite to each other, and the two second arc stripportions 220 correspond to two first edges of the bottom wall. Upon thesecond edge of the bottom wall being an arc-shaped edge, the thirdsupporting portion may also include two other arc strip portionsopposite to each other; upon the second edge of the bottom wall being astraight edge, the other two opposite strip portions included in thethird supporting portion are linear strip portions, the embodiment ofthe present disclosure is not limited thereto.

For example, as shown in FIG. 6A to FIG. 6D, the third supportingportion 230 has a third supporting surface facing the display panel 100,and the third supporting surface is provided with a buffer 102, whichcan release the acting force between the display panel and the firstmiddle frame when the display device is in a vibrating state, so as toprevent the display panel 100 from being damaged due to external force.For example, the buffer can be made of flexible materials such as foamor rubber.

For example, as shown in FIG. 6A to FIG. 6D, an inner side of the outerrim 210 surrounding the sides of the display panel 100 may also beprovided with the buffer 102. Therefore, when the side of the displaypanel faces the ground, the inner side of the first middle frame plays asupporting role on the display panel, and the buffer provided on theinner side of the first middle frame can play a protective role on thedisplay panel.

For example, as shown in FIG. 6A to FIG. 6D, one edge of the outer rim210 of the first middle frame 200 may be provided with side wallbarricades 202 and side wall openings 201 between adjacent side wallbarricades 202, and other edges of the outer rim 210 of the first middleframe 200 may be a continuous structure including connecting holes forfixing with the back plate. For example, the outer rim 210 where theside wall barricade 202 is located can be an arc-shaped outer rimcorresponding to the first arc-shaped strip, and the side wall barricade202 is used to support the display panel when a side of the displaypanel facing the side wall barricade 202 faces the ground. Therefore,the buffer arranged inside the outer rim can be the buffer arranged onan inner side of the side wall barricade.

For example, the display device further includes a circuit board (notshown) located on a surface of the first supporting portion away fromthe display panel and at the outer side of the connecting portion, andthe circuit board is connected with the display panel through wires ledout from the side wall opening of the outer rim of the first middleframe.

For example, FIG. 7A is a schematic plan view of a front frame shown inFIG. 1A and FIG. 1B, FIG. 7B is a structural schematic diagram of afront frame side wall of the front frame shown in FIG. 7A, FIG. 7C is anenlarged schematic diagram at a position E in a front frame side wall,and FIG. 7D is a partial structure diagram of a connection between thefront frame and the back plate. As shown in FIG. 1A to FIG. 7D, thefront frame 600 is located on a side of the first middle frame 200 awayfrom the backlight assembly 300, and is configured to press against thedisplay panel 100 to fix the display panel 100 on the first middle frame200. That is, the front frame contacts the display panel to fix thedisplay panel on the first middle frame.

For example, the front frame 600 may be a continuous annular structuresurrounding the display panel 100.

For example, a material of the front frame 600 can be galvanized steelplate with a thickness of 0.6 mm to 0.8 mm, and the curvature of thefront frame can be ensured by stamping forming. For example, the backplate and the front frame can be made by die-casting forming process,and the rebound and dehydration rate of the formed material is less thanthat of the stamping forming process, and the statistical tolerancecurvature can be ±1 mm.

For example, the front frame 600 may include a third arc strip portion610 located on a side of the second arc strip portion 220 away from thefirst arc strip portion. The above-mentioned third arc strip portion isa strip portion corresponding to the first edge of the bottom wall, andthe embodiment of the present disclosure determines the curvature of thedisplay panel and the first middle frame by setting the curvature of thethird arc strip portion of the front frame.

For example, the curvature of the second arc strip of the first middleframe is determined by the curvature of the third arc strip portion ofthe front frame. The material of the first middle frame in theembodiment of the disclosure adopts flexible material to bend along withthe bending of the front frame, that is, the curvature of the firstmiddle frame is determined by the curvature of the front frame on a sideof the first middle frame away from the display panel, which can bettercooperate with the front frame to ensure the curvature of the displaypanel.

For example, when the display panel is arranged between the first middleframe and the front frame, the curvature of the display panel is jointlydetermined by the curvatures of the front frame and the first middleframe.

For example, as shown in FIG. 7A to FIG. 7D, the front frame 600includes a front frame side wall 620 located on a side of the outer rim210 of the first middle frame 200 away from the side plate 420, and thefront frame side wall 620 can be fixed with the side plate of the backplate by screws.

For example, the front frame side wall 620 includes an elongated hole6200, so that the front frame side wall 620 is fixedly connected to theside plate 420 through a second fixing member 630 penetrating throughthe elongated hole 6200. The minor axis of the elongated hole 6200 isperpendicular to the first supporting surface to reduce the curvaturetolerance after the front frame and the back plate are locked, that is,to reduce the curvature influence value, and at the same time, the majoraxis is used to ensure the election deviation and improve the assemblyrate.

For example, the screw hole of the back plate may be a round hole with adiameter of 2.5 mm. The screw hole of the side wall of the front frameis an elliptical hole with a major axis of 4.4 mm and a minor axis of3.2 mm, so the curvature tolerance of the front frame is 0.7 mm.

For example, in the extending direction of the minor axis, the size ofthe second fixing member matches the size of the minor axis to realizethe accurate positioning of the front frame. That is, in the directionof the minor axis, the size of the second fixing member is approximatelyequal to that of the minor axis.

For example, along the major axis direction, the size difference betweenthe second fixing member and the major axis may be between 0.81 and 0.96mm; in the minor axis direction, the size difference between the secondfixing member and the minor axis may be between 0.31 and 0.46 mm.

The accurate positioning in the embodiment of the present disclosuremeans that the size difference between the fixing member and the fixinghole is an assembly tolerance, and the assembly tolerance is a tolerancethat exists reasonably in order to facilitate the installation of thefixing member into the fixing hole. For example, in actual products, thesize of the fixing member and the size of the fixing hole cannot becompletely the same. In order to install the fixing member into thefixing hole, the size of the fixing hole should exceed that of thefixing member, for example, the size of the fixing hole should exceedthe size of the fixing member by 0.1˜0.4 mm.

The rough positioning means that the size difference between the fixingmember and the fixing hole is greater than the assembly tolerance, sothat the fixing member and the fixing hole can move relatively in atleast one direction after being fixed. In order to realize roughpositioning, that is, allowing the fixing hole and the fixing member tomove relatively in at least one direction, the size difference betweenthe fixing member and the fixing hole will be set greater than theassembly tolerance, for example, the assembly tolerance is 0.1˜0.5 mm Incase of rough positioning, the size difference between the fixing memberand the fixing hole can be 0.81˜0.96 mm.

For example, FIG. 8 is a schematic diagram of a curvature tolerancerelationship of a display device provided by an embodiment of thepresent disclosure. Different structures of the display device in theembodiment of the present disclosure have different curvatures. In orderto ensure the assembly consideration, each assembly surface should keepthe same curvature radius. The curvature radius formula of differentstructures can be Rx=R0±h, Rx refers to the curvature radius of the Xthlayer structure, R0 refers to the curvature radius of a reference layer,and h refers to a height difference between the reference layer and theXth layer. The embodiment of the present disclosure defines thecurvature radius of an imaginary plane between an array substrate and anopposing substrate in a display panel as the curvature radius R0 of thecurved surface display device. Of course, the curvature radius of theupper surface of the display panel away from the back plate can also bedefined as R0.

As shown in FIG. 8, the curvature of the display device provided by theembodiment of the present disclosure can reach 4200R±4.5% R, and 4200Rrefers to the curvature radius of the display panel. When the back plateof curved surface display device is formed by stamping, the tolerance ofchord height of display device can be ±2 mm, and when the back plate isformed by die casting, the tolerance of chord height of display devicecan be ±1 mm. As shown in FIG. 8, the tolerance of the front framemanufactured by stamping is d1±0.2 mm, the tolerance of the first middleframe manufactured by injection molding is d2±0.05 mm, a gap between thefirst middle frame and the back plate is 0.2 mm, the tolerance of theback plate manufactured by stamping is d3±0.3 mm, the curvaturetolerance of the back plate is 0.7 mm, the deviation tolerance from thecenter of fixing hole between back plate and front frame to the surfaceof the bottom wall of back plate away from display panel is d4±0.3 mm,the manufacturing tolerance of a diameter of the screw is d7±0.05 mm,the gap between the screw and an edge of the positioning hole in thefront frame is 0.6 mm, the deviation from center of the positioning holein the front frame is d6±0.05 mm, and the deviation tolerance from acenter of the positioning hole in the front frame to a surface of thefront frame is d5±0.2 mm Therefore, the accumulated curvature toleranceis 2.65 mm. The statistical tolerance is 1.67 mm after the curvaturetolerance of a plurality of curved surface display devices in theproduction process is statistically normalized. Therefore, it can beobtained that the curvature accuracy of the display device provided bythe embodiment of the present disclosure can reach 4.5% R.

For example, the curved surface display device provided by theembodiment of the present disclosure can be a vehicle-mounted curvedsurface display device applied to an automobile.

Upon the display device provided by an example of the embodiment of thepresent disclosure being applied in a vehicle-mounted environment, thecombination of accurate positioning and rough positioning between thefirst sub-optical film and the second middle frame can ensure thefixation of the first sub-optical film and the second middle frame, andcan also ensure that the first sub-optical film is not prone to wrinklein a high-temperature and high-humidity environment, which does notaffect the normal display of the display device.

Upon the display device provided by another example of the embodiment ofthe present disclosure being applied in a vehicle-mounted environment,the combination of accurate positioning and rough positioning adoptedbetween the first sub-optical film and the second middle frame, and thecombination of accurate positioning and rough positioning adoptedbetween the second sub-optical film and the second middle frame can notonly ensure the fixation of the first sub-optical film, the secondsub-optical film and the second middle frame, but also ensure that thefirst sub-optical film and the second sub-optical film are not prone towrinkles and other deformation affecting the display in high temperatureand high humidity environment, which does not affect the display.

Upon the display device provided by another example of the embodiment ofthe present disclosure being applied in a vehicle-mounted environment,the combination of accurate positioning and rough positioning adoptedbetween the first sub-optical film and the second middle frame, thecombination of accurate positioning and rough positioning adoptedbetween the second sub-optical film and the second middle frame, and asegmented manner spliced in the reflective sheet can ensure thestability of various film fixing structures and avoid bad problems suchas scratches, white spots, tripping and the like under vehicle gaugevibration conditions.

According to another embodiment of the present disclosure, a vehicle isprovided, which includes the curved surface display device as mentionedabove.

For example, the vehicle can include a motor vehicle, an airplane, aship, a subway and other vehicles that carry people or transport goods.

For example, the motor vehicle may be a car, a truck, or the like.

The following statements should be noted:

(1) The accompanying drawings involve only the structure(s) inconnection with the embodiment(s) of the present disclosure, and otherstructure(s) can be referred to common design(s).

(2) In case of no conflict, features in one embodiment or in differentembodiments can be combined.

What are described above is related to the illustrative embodiments ofthe disclosure only and not limitative to the scope of the disclosure;the scopes of the disclosure are defined by the accompanying claims.

What is claimed is:
 1. A curved surface display device, comprises: adisplay panel; a first middle frame, located on a non-display side ofthe display panel, and configured to support the display panel; abacklight assembly, located at a side of the first middle frame awayfrom the display panel, and comprising an optical film and a secondmiddle frame, the second middle frame being located at a side of theoptical film away from the display panel and configured to support theoptical film; and a back plate, at least part of the back plate beinglocated at a side of the backlight assembly away from the display panel,wherein the back plate comprises a bottom plate and a side platedisposed on an edge of the bottom plate, and the second middle frame isconnected to the bottom plate.
 2. The curved surface display deviceaccording to claim 1, wherein the bottom plate comprises a bottom walland a first supporting portion located outside an edge of the bottomwall, the first supporting portion is located at a side of the bottomwall facing the display panel, the first supporting portion has a firstsupporting surface facing the display panel, and the second middle framecomprises a second supporting portion having a second supporting surfacefacing the display panel to support the optical film, and the secondsupporting portion is disposed on the first supporting surface of thefirst supporting portion.
 3. The curved surface display device accordingto claim 2, wherein the second supporting portion of the second middleframe is fixed to the first supporting portion by a first fixing memberin a direction perpendicular to the first supporting surface.
 4. Thecurved surface display device according to claim 3, wherein the secondsupporting portion comprises a fixing hole penetrating through thesecond supporting portion in the direction perpendicular to the firstsupporting surface, the first fixing member is located in the fixinghole, and in a direction parallel to the first supporting surface, asize of the fixing hole is greater than that of the first fixing memberso that there is a gap between the first fixing member and an inner sidewall of the fixing hole.
 5. The curved surface display device accordingto claim 1, wherein a hardness of a material of the second middle frameis greater than that of a material of the first middle frame.
 6. Thecurved surface display device according to claim 1, wherein a side ofthe first middle frame away from the display panel presses against theoptical film.
 7. The curved surface display device according to claim 4,wherein the bottom wall comprises two first edges opposite to eachother, and the first edges are arc edges; the first supporting portioncomprises first arc strip portions corresponding to the first edges, anda bending direction of the first arc strip portions is the same as thatof the first edges.
 8. The curved surface display device according toclaim 4, wherein the fixing hole is a round hole, and in a directionparallel to a diameter of the round hole, a size of the fixing hole isgreater than a size of the first fixing member.
 9. The curved surfacedisplay device according to claim 7, wherein the fixing hole is anelliptical hole, a major axis direction of the elliptical hole isparallel to the first edge, and a size of the fixing hole is greaterthan that of the first fixing member along a direction parallel to thefirst edge.
 10. The curved surface display device according to claim 2,wherein the optical film comprises a first sub-optical film including aplurality of first edge portions; the second supporting portioncomprises a plurality of rims, at least one rim is configured to supportat least one first edge portion, the at least one rim comprises a firstpositioning groove and at least one second positioning groove, the atleast one first edge portion comprises a first positioning portion andat least one second positioning portion, the first positioning portionis in the first positioning groove, and each second positioning portionis in a corresponding second positioning groove, in a normal temperatureenvironment, on each rim and the corresponding first edge portion,opposite sides of each second positioning groove in an extendingdirection of the rim are not in contact with opposite sides of thecorresponding second positioning portion in the extending direction ofthe rim, a difference between a size of the first positioning groove anda size of the first positioning portion in the extending direction ofthe rim is a first space, a difference between a size of each secondpositioning groove and a size of the corresponding second positioningportion in the extending direction of the rim is a second space, and thefirst space is smaller than the second space.
 11. The curved surfacedisplay device according to claim 10, wherein the plurality of firstedge portions comprise a first sub-edge portion extending along a firstdirection and a second sub-edge portion extending along a seconddirection, the first positioning portion on the first sub-edge portionis approximately located at a midpoint of the first sub-edge portion inthe first direction, and the at least one second positioning portioncomprises a plurality of second positioning portions, and the pluralityof second positioning portions located on the first sub-edge portion aredistributed on both sides of the first positioning portion in the firstdirection.
 12. The curved surface display device according to claim 11,wherein in the normal temperature environment, a plurality of secondspaces corresponding to the plurality of second positioning portions onthe first sub-edge portion gradually increase in a direction from themidpoint to both end points of the first sub-edge portion.
 13. Thecurved surface display device according to claim 10, wherein theplurality of first edge portions comprise a first sub-edge portionextending along a first direction and a second sub-edge portionextending along a second direction, and the at least one secondpositioning portion comprises a plurality of second positioning portionslocated on a same side of the first positioning portion on the firstsub-edge portion; in the normal temperature environment, a plurality ofsecond spaces corresponding to the plurality of second positioningportions gradually increase in a direction from a position close to thefirst positioning portion to a position away from the first positioningportion.
 14. The curved surface display device according to claim 11,wherein a length of the first sub-edge portion is greater than a lengthof the second sub-edge portion.
 15. The curved surface display deviceaccording to claim 12, wherein the first positioning portion on thefirst sub-edge portion comprises a first protruding portion, each secondpositioning portion on the first sub-edge portion comprises a secondprotruding portion, a middle part of the second protruding portioncomprises an opening, a boss is disposed in the second positioninggroove corresponding to the second positioning portion on the firstsub-edge portion, and the opening is sleeved on the boss.
 16. The curvedsurface display device according to claim 15, wherein, in the normaltemperature environment, opposite sides of each boss in the firstdirection are not in contact with opposite sides of a correspondingopening in the first direction, and a difference between a size of theopening and a size of the boss in the first direction is a third spacegreater than the first space.
 17. The curved surface display deviceaccording to claim 16, wherein a plurality of third spaces correspondingto the plurality of second positioning portions gradually increase inthe direction from the midpoint to both end points of the first sub-edgeportion.
 18. The curved surface display device according to claim 12,wherein the second space between each second positioning portion and thecorresponding second positioning groove comprises at least one of anexpansion space and a contraction space, and in the normal temperatureenvironment, in the direction from the midpoint to both end points ofthe first sub-edge portion, a plurality of expansion spacescorresponding to the plurality of second positioning portions graduallyincrease, and/or a plurality of contraction spaces corresponding to theplurality of second positioning grooves gradually increase.
 19. Thecurved surface display device according to claim 15, wherein the firstedge portion further comprises a third positioning portion and at leastone fourth positioning portion on the second sub-edge portion, and therim of the second supporting portion configured to support the secondsub-edge portion comprises a third positioning groove and at least onefourth positioning groove, the third positioning portion is in the thirdpositioning groove, and each fourth positioning portion is in acorresponding fourth positioning groove, the least one fourthpositioning portion is located on a same side of the third positioningportion in the second direction, in the normal temperature environment,opposite sides of each fourth positioning groove in the second directionare not in contact with opposite sides of the corresponding fourthpositioning portion in the second direction, and a difference between asize of the third positioning groove and a size of the third positioningportion in the second direction is smaller than a difference between asize of each fourth positioning groove and a size of a correspondingfourth positioning portion in the second direction.
 20. The curvedsurface display device according to claim 19, wherein the opening of thesecond positioning portion on the first sub-edge portion close to thethird positioning portion contacts with or keeps a small distance from aside of a corresponding boss away from the third positioning portion inthe second direction, and a space between a side of the thirdpositioning portion away from the fourth positioning portion and acorresponding side of the third positioning groove is smaller than aspace between a side the third positioning portion close to the fourthpositioning portion and a corresponding side of the third positioninggroove to realize an accurate positioning of the first sub-optical filmin the second direction; a space between the side of the thirdpositioning portion away from the fourth positioning portion and thecorresponding side of the third positioning groove is smaller than twospaces between two sides of each fourth positioning portion and acorresponding fourth positioning groove.
 21. The curved surface displaydevice according to claim 19, wherein the optical film further comprisesa second sub-optical film including a plurality of second edge portions,the second sub-optical film being located between the first sub-opticalfilm and the second supporting surface of the second middle frame, thesecond supporting surface being configured to support the secondsub-optical film and the first sub-optical film, and at least one of theplurality of rims being configured to support at least one second edgeportion; at least one rim of the second supporting portion furthercomprises a plurality of blocking walls, and at least one second edgeportion comprises a plurality of concave portions, the plurality ofconcave portions are disposed in one-to-one correspondence with theplurality of blocking walls, and each concave portion is configured tobe clamped with the corresponding blocking wall to fix the secondsub-optical film.
 22. The curved surface display device according toclaim 21, wherein the second sub-optical film comprises a third sub-edgeportion extending along the first direction and a fourth sub-edgeportion extending along the second direction; the plurality of concaveportions comprise a first sub-concave portion and a plurality of secondsub-concave portions located on the third sub-edge portion, the firstsub-concave portion is approximately located at a midpoint of the thirdsub-edge portion in the first direction, and the plurality of secondsub-concave portions are distributed on both sides of the firstsub-concave portion; in the normal temperature environment, oppositesides of each second sub-concave portion in the first direction are notin contact with opposite sides of a corresponding blocking wall in thefirst direction, a difference between a size of the first sub-concaveportion and a size of a corresponding blocking wall in the firstdirection is a fourth space, a difference between a size of the secondsub-concave portion and a size of the corresponding blocking wall in thefirst direction is a fifth space, the fourth space is smaller than thefifth space.
 23. The curved surface display device according to claim22, wherein a length of the third sub-edge portion is greater than alength of the fourth sub-edge portion; in the normal temperatureenvironment, in a direction from a middle point to both end points ofthe third sub-edge portion, a plurality of fifth spaces corresponding tothe plurality of second sub-concave portions gradually increase.
 24. Thecurved surface display device according to claim 22, wherein theplurality of concave portions comprise a third sub-concave portion andat least one fourth sub-concave portion located on the fourth sub-edgeportion, the at least one fourth sub-concave portion is located on oneside of the third sub-concave portion in the second direction, and inthe normal temperature environment, a difference between a size of thethird sub-concave portion and a size of a corresponding blocking wall inthe second direction is smaller than a difference between a size of eachfourth sub-concave portion and a size of a corresponding blocking wallin the second direction.
 25. The curved surface display device accordingto claim 21, wherein each of the plurality of blocking walls comprisestwo sub-blocking walls arranged in an extending direction of the rimwhere the blocking wall is located, and the first positioning groove,the second positioning groove, the third positioning groove or thefourth positioning groove is disposed between the two sub-blockingwalls, and in the normal temperature environment, an edge of the firstedge portion of the first sub-optical film except the first positioningportion, the second positioning portion, the third positioning portionand the fourth positioning portion has an interval with the blockingwalls.
 26. The curved surface display device according to claim 21,wherein a convex structure is disposed between two adjacent concaveportions in the plurality of concave portions, and the convex structureis located in an interval between the two adjacent blocking walls. 27.The curved surface display device according to claim 26, wherein theside plate is located outside the second supporting portion andsurrounds the second supporting portion, and comprises at least onefirst avoiding groove, and each first avoiding groove is opposite to thesecond positioning groove, the third positioning groove or the fourthpositioning groove, so that the second positioning portion extends intothe first avoiding groove after passing through a corresponding secondpositioning groove, the third positioning portion extends into the firstavoiding groove after passing through a corresponding third positioninggroove, or the fourth positioning portion extends into the firstavoiding groove after passing through a corresponding fourth positioninggroove; the side plate further comprises at least one second avoidinggroove, the second avoiding groove is opposite to the interval betweenthe two adjacent blocking walls, and the convex structure extends intothe second avoiding groove after passing through a correspondinginterval.
 28. The curved surface display device according to claim 2,wherein the bottom plate further comprises a connecting portionconnecting the edge of the bottom wall with the first supportingportion, and the first supporting portion extends outward from an edgeof the connecting portion.
 29. The curved surface display deviceaccording to claim 28, wherein the backlight assembly further comprisesa light source component including light-emitting diodes arranged in anarray, and a reflective sheet which is located on a light-emittingsurface of the light source component and exposes the light-emittingdiodes, and the light source component is disposed on a side of thebottom wall close to the display panel; the second middle frame furthercomprises an extension portion connected with the second supportingportion and partially located at an inner side of the connecting portionof the back plate, and the extension portion extends in a directionclose to the bottom wall; an end of the extension portion away from thesecond supporting portion presses against a periphery of the reflectivesheet.
 30. The curved surface display device according to claim 29,wherein an edge of the extension portion connected with the secondsupporting portion is located at an outer side of the end of theextension portion pressed against the reflective sheet, and the edge ofthe extension portion connected with the second supporting portion islocated at a side of the end of the extension portion pressed againstthe reflective sheet close to the display panel, so that an innersurface of the extension portion is formed as an inclined surface, and areflectivity of the inclined surface is not less than that of thereflective sheet.
 31. The curved surface display device according toclaim 29, wherein the bottom wall comprises two second edges opposite toeach other, the second edges are straight edges, and the light-emittingdiodes are located on a plurality of strip-shaped lamp plates, and anextending direction of each strip-shaped lamp plate is parallel to thesecond edges.
 32. The curved surface display device according to claim31, wherein the backlight assembly further comprises at least oneadapter plate located at a side of the bottom wall facing the displaypanel, and each adapter plate is connected with at least twostrip-shaped lamp plates to provide driving signals.
 33. The curvedsurface display device according to claim 32, wherein the bottom wallfurther comprises two first edges opposite to each other, and the firstedges are arc edges; the connecting portion is provided with astrip-shaped outlet hole, a part of the connecting portion provided withthe strip-shaped outlet hole is connected with the first edge of thebottom wall close to the adapter plate, and a major axis of thestrip-shaped outlet hole is parallel to the first edge; the curvedsurface display device further comprises a light source driving platelocated at a side of the bottom wall away from the display panel, andthe adapter plate is connected with the light source driving platethrough a wire led out from the strip-shaped outlet hole.
 34. The curvedsurface display device according to claim 5, wherein the side plateextends from an outer edge of the first supporting portion toward thedisplay panel, and the first middle frame comprises an outer rimsurrounding the display panel, and a part of the outer rim is located atan outer side of the side plate and fixedly connected with the sideplate; the first middle frame comprises a third supporting portionconfigured to support the display panel, and the third supportingportion has a third supporting surface facing the display panel, and thethird supporting surface and an inner side of the outer rim surroundingthe display panel are both provided with buffer members.
 35. The curvedsurface display device according to claim 34, wherein four edges of thedisplay panel are connected one by one to form four corners, and atleast one of positions of the side plate surrounding the four corners ofthe display panel and facing the third supporting surface is providedwith a groove.
 36. The curved surface display device according to claim1, wherein the curved surface display device is a vehicle-mounted curvedsurface display device.
 37. A vehicle, comprising the curved surfacedisplay device according to claim
 1. 38. A backlight assembly,comprising: an optical film, comprising a plurality of edge portions; asupporting frame, comprising a supporting portion, the supportingportion having a supporting surface facing the optical film to supportthe optical film, the supporting portion comprising a plurality of rims,at least one rim being configured to support at least one edge portion,wherein the at least one rim comprises a first positioning groove and atleast one second positioning groove, the at least one edge portioncomprises a first positioning portion and at least one secondpositioning portion, the first positioning portion is in the firstpositioning groove, and each second positioning portion is in acorresponding second positioning groove, in a normal temperatureenvironment, on each rim and the corresponding edge portion, oppositesides of each second positioning groove in an extending direction of therim are not in contact with opposite sides of the corresponding secondpositioning portion in the extending direction of the rim, a differencebetween a size of the first positioning groove and a size of the firstpositioning portion in the extending direction of the rim is a firstspace, a difference between a size of each second positioning groove anda size of the corresponding second positioning portion in the extendingdirection of the rim is a second space, and the first space is smallerthan the second space.